Datasets:

DenCT
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codeforces-problems-7k

contestId int64 0 1.01k	name stringlengths 2 58	tags sequencelengths 0 11	title stringclasses 523 values	time-limit stringclasses 8 values	memory-limit stringclasses 8 values	problem-description stringlengths 0 7.15k	input-specification stringlengths 0 2.05k	output-specification stringlengths 0 1.5k	demo-input sequencelengths 0 7	demo-output sequencelengths 0 7	note stringlengths 0 5.24k	test_cases listlengths 0 402	timeConsumedMillis int64 0 8k	memoryConsumedBytes int64 0 537M	score float64 -1 3.99	__index_level_0__ int64 0 621k
315	Sereja and Bottles	[ "brute force" ]		null	null	Sereja and his friends went to a picnic. The guys had n soda bottles just for it. Sereja forgot the bottle opener as usual, so the guys had to come up with another way to open bottles. Sereja knows that the i-th bottle is from brand ai, besides, you can use it to open other bottles of brand bi. You can use one bottle to open multiple other bottles. Sereja can open bottle with opened bottle or closed bottle. Knowing this, Sereja wants to find out the number of bottles they've got that they won't be able to open in any way. Help him and find this number.	The first line contains integer n (1<=≤<=n<=≤<=100) — the number of bottles. The next n lines contain the bottles' description. The i-th line contains two integers ai,<=bi (1<=≤<=ai,<=bi<=≤<=1000) — the description of the i-th bottle.	In a single line print a single integer — the answer to the problem.	[ "4\n1 1\n2 2\n3 3\n4 4\n", "4\n1 2\n2 3\n3 4\n4 1\n" ]	[ "4\n", "0\n" ]	none	[ { "input": "4\n1 1\n2 2\n3 3\n4 4", "output": "4" }, { "input": "4\n1 2\n2 3\n3 4\n4 1", "output": "0" }, { "input": "3\n2 828\n4 392\n4 903", "output": "3" }, { "input": "4\n2 3\n1 772\n3 870\n3 668", "output": "2" }, { "input": "5\n1 4\n6 6\n4 3\n3 4\n4 758", ...	154	3,379,200	-1	0
233	Perfect Permutation	[ "implementation", "math" ]		null	null	A permutation is a sequence of integers p1,<=p2,<=...,<=pn, consisting of n distinct positive integers, each of them doesn't exceed n. Let's denote the i-th element of permutation p as pi. We'll call number n the size of permutation p1,<=p2,<=...,<=pn. Nickolas adores permutations. He likes some permutations more than the others. He calls such permutations perfect. A perfect permutation is such permutation p that for any i (1<=≤<=i<=≤<=n) (n is the permutation size) the following equations hold ppi<==<=i and pi<=≠<=i. Nickolas asks you to print any perfect permutation of size n for the given n.	A single line contains a single integer n (1<=≤<=n<=≤<=100) — the permutation size.	If a perfect permutation of size n doesn't exist, print a single integer -1. Otherwise print n distinct integers from 1 to n, p1,<=p2,<=...,<=pn — permutation p, that is perfect. Separate printed numbers by whitespaces.	[ "1\n", "2\n", "4\n" ]	[ "-1\n", "2 1 \n", "2 1 4 3 \n" ]	none	[ { "input": "1", "output": "-1" }, { "input": "2", "output": "2 1 " }, { "input": "4", "output": "2 1 4 3 " }, { "input": "3", "output": "-1" }, { "input": "5", "output": "-1" }, { "input": "6", "output": "2 1 4 3 6 5 " }, { "input": "7", ...	92	0	-1	1
34	Reconnaissance 2	[ "implementation" ]	A. Reconnaissance 2	2	256	n soldiers stand in a circle. For each soldier his height ai is known. A reconnaissance unit can be made of such two neighbouring soldiers, whose heights difference is minimal, i.e. \|ai<=-<=aj\| is minimal. So each of them will be less noticeable with the other. Output any pair of soldiers that can form a reconnaissance unit.	The first line contains integer n (2<=≤<=n<=≤<=100) — amount of soldiers. Then follow the heights of the soldiers in their order in the circle — n space-separated integers a1,<=a2,<=...,<=an (1<=≤<=ai<=≤<=1000). The soldier heights are given in clockwise or counterclockwise direction.	Output two integers — indexes of neighbouring soldiers, who should form a reconnaissance unit. If there are many optimum solutions, output any of them. Remember, that the soldiers stand in a circle.	[ "5\n10 12 13 15 10\n", "4\n10 20 30 40\n" ]	[ "5 1\n", "1 2\n" ]	none	[ { "input": "5\n10 12 13 15 10", "output": "5 1" }, { "input": "4\n10 20 30 40", "output": "1 2" }, { "input": "6\n744 359 230 586 944 442", "output": "2 3" }, { "input": "5\n826 747 849 687 437", "output": "1 2" }, { "input": "5\n999 999 993 969 999", "output"...	218	307,200	3.944928	2
707	Brain's Photos	[ "implementation" ]		null	null	Small, but very brave, mouse Brain was not accepted to summer school of young villains. He was upset and decided to postpone his plans of taking over the world, but to become a photographer instead. As you may know, the coolest photos are on the film (because you can specify the hashtag #film for such). Brain took a lot of colourful pictures on colored and black-and-white film. Then he developed and translated it into a digital form. But now, color and black-and-white photos are in one folder, and to sort them, one needs to spend more than one hour! As soon as Brain is a photographer not programmer now, he asks you to help him determine for a single photo whether it is colored or black-and-white. Photo can be represented as a matrix sized n<=×<=m, and each element of the matrix stores a symbol indicating corresponding pixel color. There are only 6 colors: - 'C' (cyan)- 'M' (magenta)- 'Y' (yellow)- 'W' (white)- 'G' (grey)- 'B' (black) The photo is considered black-and-white if it has only white, black and grey pixels in it. If there are any of cyan, magenta or yellow pixels in the photo then it is considered colored.	The first line of the input contains two integers n and m (1<=≤<=n,<=m<=≤<=100) — the number of photo pixel matrix rows and columns respectively. Then n lines describing matrix rows follow. Each of them contains m space-separated characters describing colors of pixels in a row. Each character in the line is one of the 'C', 'M', 'Y', 'W', 'G' or 'B'.	Print the "#Black&White" (without quotes), if the photo is black-and-white and "#Color" (without quotes), if it is colored, in the only line.	[ "2 2\nC M\nY Y\n", "3 2\nW W\nW W\nB B\n", "1 1\nW\n" ]	[ "#Color", "#Black&White", "#Black&White" ]	none	[ { "input": "2 2\nC M\nY Y", "output": "#Color" }, { "input": "3 2\nW W\nW W\nB B", "output": "#Black&White" }, { "input": "1 1\nW", "output": "#Black&White" }, { "input": "2 3\nW W W\nB G Y", "output": "#Color" }, { "input": "1 1\nW", "output": "#Black&White" ...	31	0	0	3
507	Amr and Music	[ "greedy", "implementation", "sortings" ]		null	null	Amr is a young coder who likes music a lot. He always wanted to learn how to play music but he was busy coding so he got an idea. Amr has n instruments, it takes ai days to learn i-th instrument. Being busy, Amr dedicated k days to learn how to play the maximum possible number of instruments. Amr asked for your help to distribute his free days between instruments so that he can achieve his goal.	The first line contains two numbers n, k (1<=≤<=n<=≤<=100, 0<=≤<=k<=≤<=10<=000), the number of instruments and number of days respectively. The second line contains n integers ai (1<=≤<=ai<=≤<=100), representing number of days required to learn the i-th instrument.	In the first line output one integer m representing the maximum number of instruments Amr can learn. In the second line output m space-separated integers: the indices of instruments to be learnt. You may output indices in any order. if there are multiple optimal solutions output any. It is not necessary to use all days for studying.	[ "4 10\n4 3 1 2\n", "5 6\n4 3 1 1 2\n", "1 3\n4\n" ]	[ "4\n1 2 3 4", "3\n1 3 4", "0\n" ]	In the first test Amr can learn all 4 instruments. In the second test other possible solutions are: {2, 3, 5} or {3, 4, 5}. In the third test Amr doesn't have enough time to learn the only presented instrument.	[ { "input": "4 10\n4 3 1 2", "output": "4\n1 2 3 4" }, { "input": "5 6\n4 3 1 1 2", "output": "3\n3 4 5" }, { "input": "1 3\n4", "output": "0" }, { "input": "2 100\n100 100", "output": "1\n1" }, { "input": "3 150\n50 50 50", "output": "3\n1 2 3" }, { "i...	109	0	3	4
41	Translation	[ "implementation", "strings" ]	A. Translation	2	256	The translation from the Berland language into the Birland language is not an easy task. Those languages are very similar: a berlandish word differs from a birlandish word with the same meaning a little: it is spelled (and pronounced) reversely. For example, a Berlandish word code corresponds to a Birlandish word edoc. However, it's easy to make a mistake during the «translation». Vasya translated word s from Berlandish into Birlandish as t. Help him: find out if he translated the word correctly.	The first line contains word s, the second line contains word t. The words consist of lowercase Latin letters. The input data do not consist unnecessary spaces. The words are not empty and their lengths do not exceed 100 symbols.	If the word t is a word s, written reversely, print YES, otherwise print NO.	[ "code\nedoc\n", "abb\naba\n", "code\ncode\n" ]	[ "YES\n", "NO\n", "NO\n" ]	none	[ { "input": "code\nedoc", "output": "YES" }, { "input": "abb\naba", "output": "NO" }, { "input": "code\ncode", "output": "NO" }, { "input": "abacaba\nabacaba", "output": "YES" }, { "input": "q\nq", "output": "YES" }, { "input": "asrgdfngfnmfgnhweratgjkk...	154	0	3.9615	5
732	Buy a Shovel	[ "brute force", "constructive algorithms", "implementation", "math" ]		null	null	Polycarp urgently needs a shovel! He comes to the shop and chooses an appropriate one. The shovel that Policarp chooses is sold for k burles. Assume that there is an unlimited number of such shovels in the shop. In his pocket Polycarp has an unlimited number of "10-burle coins" and exactly one coin of r burles (1<=≤<=r<=≤<=9). What is the minimum number of shovels Polycarp has to buy so that he can pay for the purchase without any change? It is obvious that he can pay for 10 shovels without any change (by paying the requied amount of 10-burle coins and not using the coin of r burles). But perhaps he can buy fewer shovels and pay without any change. Note that Polycarp should buy at least one shovel.	The single line of input contains two integers k and r (1<=≤<=k<=≤<=1000, 1<=≤<=r<=≤<=9) — the price of one shovel and the denomination of the coin in Polycarp's pocket that is different from "10-burle coins". Remember that he has an unlimited number of coins in the denomination of 10, that is, Polycarp has enough money to buy any number of shovels.	Print the required minimum number of shovels Polycarp has to buy so that he can pay for them without any change.	[ "117 3\n", "237 7\n", "15 2\n" ]	[ "9\n", "1\n", "2\n" ]	In the first example Polycarp can buy 9 shovels and pay 9·117 = 1053 burles. Indeed, he can pay this sum by using 10-burle coins and one 3-burle coin. He can't buy fewer shovels without any change. In the second example it is enough for Polycarp to buy one shovel. In the third example Polycarp should buy two shovels and pay 2·15 = 30 burles. It is obvious that he can pay this sum without any change.	[ { "input": "117 3", "output": "9" }, { "input": "237 7", "output": "1" }, { "input": "15 2", "output": "2" }, { "input": "1 1", "output": "1" }, { "input": "1 9", "output": "9" }, { "input": "1000 3", "output": "1" }, { "input": "1000 1", ...	46	0	0	6
334	Candy Bags	[ "implementation" ]		null	null	Gerald has n younger brothers and their number happens to be even. One day he bought n2 candy bags. One bag has one candy, one bag has two candies, one bag has three candies and so on. In fact, for each integer k from 1 to n2 he has exactly one bag with k candies. Help him give n bags of candies to each brother so that all brothers got the same number of candies.	The single line contains a single integer n (n is even, 2<=≤<=n<=≤<=100) — the number of Gerald's brothers.	Let's assume that Gerald indexes his brothers with numbers from 1 to n. You need to print n lines, on the i-th line print n integers — the numbers of candies in the bags for the i-th brother. Naturally, all these numbers should be distinct and be within limits from 1 to n2. You can print the numbers in the lines in any order. It is guaranteed that the solution exists at the given limits.	[ "2\n" ]	[ "1 4\n2 3\n" ]	The sample shows Gerald's actions if he has two brothers. In this case, his bags contain 1, 2, 3 and 4 candies. He can give the bags with 1 and 4 candies to one brother and the bags with 2 and 3 to the other brother.	[ { "input": "2", "output": "1 4\n2 3" }, { "input": "4", "output": "1 16 2 15\n3 14 4 13\n5 12 6 11\n7 10 8 9" }, { "input": "6", "output": "1 36 2 35 3 34\n4 33 5 32 6 31\n7 30 8 29 9 28\n10 27 11 26 12 25\n13 24 14 23 15 22\n16 21 17 20 18 19" }, { "input": "8", "output"...	156	307,200	3	7
862	Mahmoud and Ehab and the MEX	[ "greedy", "implementation" ]		null	null	Dr. Evil kidnapped Mahmoud and Ehab in the evil land because of their performance in the Evil Olympiad in Informatics (EOI). He decided to give them some problems to let them go. Dr. Evil is interested in sets, He has a set of n integers. Dr. Evil calls a set of integers evil if the MEX of it is exactly x. the MEX of a set of integers is the minimum non-negative integer that doesn't exist in it. For example, the MEX of the set {0,<=2,<=4} is 1 and the MEX of the set {1,<=2,<=3} is 0 . Dr. Evil is going to make his set evil. To do this he can perform some operations. During each operation he can add some non-negative integer to his set or erase some element from it. What is the minimal number of operations Dr. Evil has to perform to make his set evil?	The first line contains two integers n and x (1<=≤<=n<=≤<=100, 0<=≤<=x<=≤<=100) — the size of the set Dr. Evil owns, and the desired MEX. The second line contains n distinct non-negative integers not exceeding 100 that represent the set.	The only line should contain one integer — the minimal number of operations Dr. Evil should perform.	[ "5 3\n0 4 5 6 7\n", "1 0\n0\n", "5 0\n1 2 3 4 5\n" ]	[ "2\n", "1\n", "0\n" ]	For the first test case Dr. Evil should add 1 and 2 to the set performing 2 operations. For the second test case Dr. Evil should erase 0 from the set. After that, the set becomes empty, so the MEX of it is 0. In the third test case the set is already evil.	[ { "input": "5 3\n0 4 5 6 7", "output": "2" }, { "input": "1 0\n0", "output": "1" }, { "input": "5 0\n1 2 3 4 5", "output": "0" }, { "input": "10 5\n57 1 47 9 93 37 76 70 78 15", "output": "4" }, { "input": "10 5\n99 98 93 97 95 100 92 94 91 96", "output": "5" ...	109	0	3	8
424	Squats	[ "implementation" ]		null	null	Pasha has many hamsters and he makes them work out. Today, n hamsters (n is even) came to work out. The hamsters lined up and each hamster either sat down or stood up. For another exercise, Pasha needs exactly hamsters to stand up and the other hamsters to sit down. In one minute, Pasha can make some hamster ether sit down or stand up. How many minutes will he need to get what he wants if he acts optimally well?	The first line contains integer n (2<=≤<=n<=≤<=200; n is even). The next line contains n characters without spaces. These characters describe the hamsters' position: the i-th character equals 'X', if the i-th hamster in the row is standing, and 'x', if he is sitting.	In the first line, print a single integer — the minimum required number of minutes. In the second line, print a string that describes the hamsters' position after Pasha makes the required changes. If there are multiple optimal positions, print any of them.	[ "4\nxxXx\n", "2\nXX\n", "6\nxXXxXx\n" ]	[ "1\nXxXx\n", "1\nxX\n", "0\nxXXxXx\n" ]	none	[ { "input": "4\nxxXx", "output": "1\nXxXx" }, { "input": "2\nXX", "output": "1\nxX" }, { "input": "6\nxXXxXx", "output": "0\nxXXxXx" }, { "input": "4\nxXXX", "output": "1\nxxXX" }, { "input": "2\nXx", "output": "0\nXx" }, { "input": "22\nXXxXXxxXxXxXXXX...	62	0	0	9
630	Moore's Law	[ "math" ]		null	null	The city administration of IT City decided to fix up a symbol of scientific and technical progress in the city's main square, namely an indicator board that shows the effect of Moore's law in real time. Moore's law is the observation that the number of transistors in a dense integrated circuit doubles approximately every 24 months. The implication of Moore's law is that computer performance as function of time increases exponentially as well. You are to prepare information that will change every second to display on the indicator board. Let's assume that every second the number of transistors increases exactly 1.000000011 times.	The only line of the input contains a pair of integers n (1000<=≤<=n<=≤<=10 000) and t (0<=≤<=t<=≤<=2 000 000 000) — the number of transistors in the initial time and the number of seconds passed since the initial time.	Output one number — the estimate of the number of transistors in a dence integrated circuit in t seconds since the initial time. The relative error of your answer should not be greater than 10<=-<=6.	[ "1000 1000000\n" ]	[ "1011.060722383550382782399454922040\n" ]	none	[ { "input": "1000 1000000", "output": "1011.060722383550382782399454922040" }, { "input": "1000 0", "output": "1000" }, { "input": "1000 1", "output": "1000.000011000" }, { "input": "1000 2", "output": "1000.000022000000121000" }, { "input": "10000 3", "output"...	46	0	3	10
257	Sockets	[ "greedy", "implementation", "sortings" ]		null	null	Vasya has got many devices that work on electricity. He's got n supply-line filters to plug the devices, the i-th supply-line filter has ai sockets. Overall Vasya has got m devices and k electrical sockets in his flat, he can plug the devices or supply-line filters directly. Of course, he can plug the supply-line filter to any other supply-line filter. The device (or the supply-line filter) is considered plugged to electricity if it is either plugged to one of k electrical sockets, or if it is plugged to some supply-line filter that is in turn plugged to electricity. What minimum number of supply-line filters from the given set will Vasya need to plug all the devices he has to electricity? Note that all devices and supply-line filters take one socket for plugging and that he can use one socket to plug either one device or one supply-line filter.	The first line contains three integers n, m, k (1<=≤<=n,<=m,<=k<=≤<=50) — the number of supply-line filters, the number of devices and the number of sockets that he can plug to directly, correspondingly. The second line contains n space-separated integers a1,<=a2,<=...,<=an (1<=≤<=ai<=≤<=50) — number ai stands for the number of sockets on the i-th supply-line filter.	Print a single number — the minimum number of supply-line filters that is needed to plug all the devices to electricity. If it is impossible to plug all the devices even using all the supply-line filters, print -1.	[ "3 5 3\n3 1 2\n", "4 7 2\n3 3 2 4\n", "5 5 1\n1 3 1 2 1\n" ]	[ "1\n", "2\n", "-1\n" ]	In the first test case he can plug the first supply-line filter directly to electricity. After he plug it, he get 5 (3 on the supply-line filter and 2 remaining sockets for direct plugging) available sockets to plug. Thus, one filter is enough to plug 5 devices. One of the optimal ways in the second test sample is to plug the second supply-line filter directly and plug the fourth supply-line filter to one of the sockets in the second supply-line filter. Thus, he gets exactly 7 sockets, available to plug: one to plug to the electricity directly, 2 on the second supply-line filter, 4 on the fourth supply-line filter. There's no way he can plug 7 devices if he use one supply-line filter.	[ { "input": "3 5 3\n3 1 2", "output": "1" }, { "input": "4 7 2\n3 3 2 4", "output": "2" }, { "input": "5 5 1\n1 3 1 2 1", "output": "-1" }, { "input": "4 5 8\n3 2 4 3", "output": "0" }, { "input": "5 10 1\n4 3 4 2 4", "output": "3" }, { "input": "7 13 2...	280	20,172,800	0	11
409	A + B Strikes Back	[ "*special", "brute force", "constructive algorithms", "dsu", "implementation" ]		null	null	A + B is often used as an example of the easiest problem possible to show some contest platform. However, some scientists have observed that sometimes this problem is not so easy to get accepted. Want to try?	The input contains two integers a and b (0<=≤<=a,<=b<=≤<=103), separated by a single space.	Output the sum of the given integers.	[ "5 14\n", "381 492\n" ]	[ "19\n", "873\n" ]	none	[ { "input": "5 14", "output": "19" }, { "input": "381 492", "output": "873" }, { "input": "536 298", "output": "834" }, { "input": "143 522", "output": "665" }, { "input": "433 126", "output": "559" }, { "input": "723 350", "output": "1073" }, {...	0	0	0	12
268	Games	[ "brute force" ]		null	null	Manao works on a sports TV. He's spent much time watching the football games of some country. After a while he began to notice different patterns. For example, each team has two sets of uniforms: home uniform and guest uniform. When a team plays a game at home, the players put on the home uniform. When a team plays as a guest on somebody else's stadium, the players put on the guest uniform. The only exception to that rule is: when the home uniform color of the host team matches the guests' uniform, the host team puts on its guest uniform as well. For each team the color of the home and guest uniform is different. There are n teams taking part in the national championship. The championship consists of n·(n<=-<=1) games: each team invites each other team to its stadium. At this point Manao wondered: how many times during the championship is a host team going to put on the guest uniform? Note that the order of the games does not affect this number. You know the colors of the home and guest uniform for each team. For simplicity, the colors are numbered by integers in such a way that no two distinct colors have the same number. Help Manao find the answer to his question.	The first line contains an integer n (2<=≤<=n<=≤<=30). Each of the following n lines contains a pair of distinct space-separated integers hi, ai (1<=≤<=hi,<=ai<=≤<=100) — the colors of the i-th team's home and guest uniforms, respectively.	In a single line print the number of games where the host team is going to play in the guest uniform.	[ "3\n1 2\n2 4\n3 4\n", "4\n100 42\n42 100\n5 42\n100 5\n", "2\n1 2\n1 2\n" ]	[ "1\n", "5\n", "0\n" ]	In the first test case the championship consists of 6 games. The only game with the event in question is the game between teams 2 and 1 on the stadium of team 2. In the second test sample the host team will have to wear guest uniform in the games between teams: 1 and 2, 2 and 1, 2 and 3, 3 and 4, 4 and 2 (the host team is written first).	[ { "input": "3\n1 2\n2 4\n3 4", "output": "1" }, { "input": "4\n100 42\n42 100\n5 42\n100 5", "output": "5" }, { "input": "2\n1 2\n1 2", "output": "0" }, { "input": "7\n4 7\n52 55\n16 4\n55 4\n20 99\n3 4\n7 52", "output": "6" }, { "input": "10\n68 42\n1 35\n25 70\n...	216	0	3	13
368	Sereja and Suffixes	[ "data structures", "dp" ]		null	null	Sereja has an array a, consisting of n integers a1, a2, ..., an. The boy cannot sit and do nothing, he decided to study an array. Sereja took a piece of paper and wrote out m integers l1,<=l2,<=...,<=lm (1<=≤<=li<=≤<=n). For each number li he wants to know how many distinct numbers are staying on the positions li, li<=+<=1, ..., n. Formally, he want to find the number of distinct numbers among ali,<=ali<=+<=1,<=...,<=an.? Sereja wrote out the necessary array elements but the array was so large and the boy was so pressed for time. Help him, find the answer for the described question for each li.	The first line contains two integers n and m (1<=≤<=n,<=m<=≤<=105). The second line contains n integers a1, a2, ..., an (1<=≤<=ai<=≤<=105) — the array elements. Next m lines contain integers l1,<=l2,<=...,<=lm. The i-th line contains integer li (1<=≤<=li<=≤<=n).	Print m lines — on the i-th line print the answer to the number li.	[ "10 10\n1 2 3 4 1 2 3 4 100000 99999\n1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n" ]	[ "6\n6\n6\n6\n6\n5\n4\n3\n2\n1\n" ]	none	[ { "input": "10 10\n1 2 3 4 1 2 3 4 100000 99999\n1\n2\n3\n4\n5\n6\n7\n8\n9\n10", "output": "6\n6\n6\n6\n6\n5\n4\n3\n2\n1" }, { "input": "8 3\n8 6 4 3 4 2 4 8\n6\n4\n2", "output": "3\n4\n5" }, { "input": "7 10\n1 3 8 6 2 2 7\n4\n2\n6\n3\n4\n4\n6\n2\n7\n4", "output": "3\n5\n2\n4\n3\n3\...	15	0	0	14
604	Uncowed Forces	[ "implementation" ]		null	null	Kevin Sun has just finished competing in Codeforces Round #334! The round was 120 minutes long and featured five problems with maximum point values of 500, 1000, 1500, 2000, and 2500, respectively. Despite the challenging tasks, Kevin was uncowed and bulldozed through all of them, distinguishing himself from the herd as the best cowmputer scientist in all of Bovinia. Kevin knows his submission time for each problem, the number of wrong submissions that he made on each problem, and his total numbers of successful and unsuccessful hacks. Because Codeforces scoring is complicated, Kevin wants you to write a program to compute his final score. Codeforces scores are computed as follows: If the maximum point value of a problem is x, and Kevin submitted correctly at minute m but made w wrong submissions, then his score on that problem is . His total score is equal to the sum of his scores for each problem. In addition, Kevin's total score gets increased by 100 points for each successful hack, but gets decreased by 50 points for each unsuccessful hack. All arithmetic operations are performed with absolute precision and no rounding. It is guaranteed that Kevin's final score is an integer.	The first line of the input contains five space-separated integers m1, m2, m3, m4, m5, where mi (0<=≤<=mi<=≤<=119) is the time of Kevin's last submission for problem i. His last submission is always correct and gets accepted. The second line contains five space-separated integers w1, w2, w3, w4, w5, where wi (0<=≤<=wi<=≤<=10) is Kevin's number of wrong submissions on problem i. The last line contains two space-separated integers hs and hu (0<=≤<=hs,<=hu<=≤<=20), denoting the Kevin's numbers of successful and unsuccessful hacks, respectively.	Print a single integer, the value of Kevin's final score.	[ "20 40 60 80 100\n0 1 2 3 4\n1 0\n", "119 119 119 119 119\n0 0 0 0 0\n10 0\n" ]	[ "4900\n", "4930\n" ]	In the second sample, Kevin takes 119 minutes on all of the problems. Therefore, he gets <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/42158dc2bc78cd21fa679530ae9ef8b9ea298d15.png" style="max-width: 100.0%;max-height: 100.0%;"/> of the points on each problem. So his score from solving problems is <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/fdf392d8508500b57f8057ac0c4c892ab5f925a2.png" style="max-width: 100.0%;max-height: 100.0%;"/>. Adding in 10·100 = 1000 points from hacks, his total score becomes 3930 + 1000 = 4930.	[ { "input": "20 40 60 80 100\n0 1 2 3 4\n1 0", "output": "4900" }, { "input": "119 119 119 119 119\n0 0 0 0 0\n10 0", "output": "4930" }, { "input": "3 6 13 38 60\n6 10 10 3 8\n9 9", "output": "5088" }, { "input": "21 44 11 68 75\n6 2 4 8 4\n2 8", "output": "4522" }, {...	46	0	3	15
522	Photo to Remember	[ "*special", "data structures", "dp", "implementation" ]		null	null	One day n friends met at a party, they hadn't seen each other for a long time and so they decided to make a group photo together. Simply speaking, the process of taking photos can be described as follows. On the photo, each photographed friend occupies a rectangle of pixels: the i-th of them occupies the rectangle of width wi pixels and height hi pixels. On the group photo everybody stands in a line, thus the minimum pixel size of the photo including all the photographed friends, is W<=×<=H, where W is the total sum of all widths and H is the maximum height of all the photographed friends. As is usually the case, the friends made n photos — the j-th (1<=≤<=j<=≤<=n) photo had everybody except for the j-th friend as he was the photographer. Print the minimum size of each made photo in pixels.	The first line contains integer n (2<=≤<=n<=≤<=200<=000) — the number of friends. Then n lines follow: the i-th line contains information about the i-th friend. The line contains a pair of integers wi,<=hi (1<=≤<=wi<=≤<=10,<=1<=≤<=hi<=≤<=1000) — the width and height in pixels of the corresponding rectangle.	Print n space-separated numbers b1,<=b2,<=...,<=bn, where bi — the total number of pixels on the minimum photo containing all friends expect for the i-th one.	[ "3\n1 10\n5 5\n10 1\n", "3\n2 1\n1 2\n2 1\n" ]	[ "75 110 60 ", "6 4 6 " ]	none	[ { "input": "3\n1 10\n5 5\n10 1", "output": "75 110 60 " }, { "input": "3\n2 1\n1 2\n2 1", "output": "6 4 6 " }, { "input": "2\n1 5\n2 3", "output": "6 5 " }, { "input": "2\n2 3\n1 1", "output": "1 6 " }, { "input": "3\n1 10\n2 10\n3 10", "output": "50 40 30 " ...	1,731	18,534,400	3	16
714	Meeting of Old Friends	[ "implementation", "math" ]		null	null	Today an outstanding event is going to happen in the forest — hedgehog Filya will come to his old fried Sonya! Sonya is an owl and she sleeps during the day and stay awake from minute l1 to minute r1 inclusive. Also, during the minute k she prinks and is unavailable for Filya. Filya works a lot and he plans to visit Sonya from minute l2 to minute r2 inclusive. Calculate the number of minutes they will be able to spend together.	The only line of the input contains integers l1, r1, l2, r2 and k (1<=≤<=l1,<=r1,<=l2,<=r2,<=k<=≤<=1018, l1<=≤<=r1, l2<=≤<=r2), providing the segments of time for Sonya and Filya and the moment of time when Sonya prinks.	Print one integer — the number of minutes Sonya and Filya will be able to spend together.	[ "1 10 9 20 1\n", "1 100 50 200 75\n" ]	[ "2\n", "50\n" ]	In the first sample, they will be together during minutes 9 and 10. In the second sample, they will be together from minute 50 to minute 74 and from minute 76 to minute 100.	[ { "input": "1 10 9 20 1", "output": "2" }, { "input": "1 100 50 200 75", "output": "50" }, { "input": "6 6 5 8 9", "output": "1" }, { "input": "1 1000000000 1 1000000000 1", "output": "999999999" }, { "input": "5 100 8 8 8", "output": "0" }, { "input":...	46	6,758,400	0	17
855	Helga Hufflepuff's Cup	[ "dp", "trees" ]		null	null	Harry, Ron and Hermione have figured out that Helga Hufflepuff's cup is a horcrux. Through her encounter with Bellatrix Lestrange, Hermione came to know that the cup is present in Bellatrix's family vault in Gringott's Wizarding Bank. The Wizarding bank is in the form of a tree with total n vaults where each vault has some type, denoted by a number between 1 to m. A tree is an undirected connected graph with no cycles. The vaults with the highest security are of type k, and all vaults of type k have the highest security. There can be at most x vaults of highest security. Also, if a vault is of the highest security, its adjacent vaults are guaranteed to not be of the highest security and their type is guaranteed to be less than k. Harry wants to consider every possibility so that he can easily find the best path to reach Bellatrix's vault. So, you have to tell him, given the tree structure of Gringotts, the number of possible ways of giving each vault a type such that the above conditions hold.	The first line of input contains two space separated integers, n and m — the number of vaults and the number of different vault types possible. (1<=≤<=n<=≤<=105,<=1<=≤<=m<=≤<=109). Each of the next n<=-<=1 lines contain two space separated integers ui and vi (1<=≤<=ui,<=vi<=≤<=n) representing the i-th edge, which shows there is a path between the two vaults ui and vi. It is guaranteed that the given graph is a tree. The last line of input contains two integers k and x (1<=≤<=k<=≤<=m,<=1<=≤<=x<=≤<=10), the type of the highest security vault and the maximum possible number of vaults of highest security.	Output a single integer, the number of ways of giving each vault a type following the conditions modulo 109<=+<=7.	[ "4 2\n1 2\n2 3\n1 4\n1 2\n", "3 3\n1 2\n1 3\n2 1\n", "3 1\n1 2\n1 3\n1 1\n" ]	[ "1\n", "13\n", "0\n" ]	In test case 1, we cannot have any vault of the highest security as its type is 1 implying that its adjacent vaults would have to have a vault type less than 1, which is not allowed. Thus, there is only one possible combination, in which all the vaults have type 2.	[ { "input": "4 2\n1 2\n2 3\n1 4\n1 2", "output": "1" }, { "input": "3 3\n1 2\n1 3\n2 1", "output": "13" }, { "input": "3 1\n1 2\n1 3\n1 1", "output": "0" }, { "input": "3 1000000000\n2 3\n3 1\n585430050 9", "output": "91592837" }, { "input": "4 50000\n2 1\n4 2\n2 3...	77	0	0	18
559	Equivalent Strings	[ "divide and conquer", "hashing", "sortings", "strings" ]		null	null	Today on a lecture about strings Gerald learned a new definition of string equivalency. Two strings a and b of equal length are called equivalent in one of the two cases: 1. They are equal. 1. If we split string a into two halves of the same size a1 and a2, and string b into two halves of the same size b1 and b2, then one of the following is correct: a1 is equivalent to b1, and a2 is equivalent to b2 1. a1 is equivalent to b2, and a2 is equivalent to b1 As a home task, the teacher gave two strings to his students and asked to determine if they are equivalent. Gerald has already completed this home task. Now it's your turn!	The first two lines of the input contain two strings given by the teacher. Each of them has the length from 1 to 200<=000 and consists of lowercase English letters. The strings have the same length.	Print "YES" (without the quotes), if these two strings are equivalent, and "NO" (without the quotes) otherwise.	[ "aaba\nabaa\n", "aabb\nabab\n" ]	[ "YES\n", "NO\n" ]	In the first sample you should split the first string into strings "aa" and "ba", the second one — into strings "ab" and "aa". "aa" is equivalent to "aa"; "ab" is equivalent to "ba" as "ab" = "a" + "b", "ba" = "b" + "a". In the second sample the first string can be splitted into strings "aa" and "bb", that are equivalent only to themselves. That's why string "aabb" is equivalent only to itself and to string "bbaa".	[ { "input": "aaba\nabaa", "output": "YES" }, { "input": "aabb\nabab", "output": "NO" }, { "input": "a\na", "output": "YES" }, { "input": "a\nb", "output": "NO" }, { "input": "ab\nab", "output": "YES" }, { "input": "ab\nba", "output": "YES" }, { ...	2,000	1,638,400	0	19
702	Powers of Two	[ "brute force", "data structures", "implementation", "math" ]		null	null	You are given n integers a1,<=a2,<=...,<=an. Find the number of pairs of indexes i,<=j (i<=<<=j) that ai<=+<=aj is a power of 2 (i. e. some integer x exists so that ai<=+<=aj<==<=2x).	The first line contains the single positive integer n (1<=≤<=n<=≤<=105) — the number of integers. The second line contains n positive integers a1,<=a2,<=...,<=an (1<=≤<=ai<=≤<=109).	Print the number of pairs of indexes i,<=j (i<=<<=j) that ai<=+<=aj is a power of 2.	[ "4\n7 3 2 1\n", "3\n1 1 1\n" ]	[ "2\n", "3\n" ]	In the first example the following pairs of indexes include in answer: (1, 4) and (2, 4). In the second example all pairs of indexes (i, j) (where i < j) include in answer.	[ { "input": "4\n7 3 2 1", "output": "2" }, { "input": "3\n1 1 1", "output": "3" }, { "input": "1\n1000000000", "output": "0" }, { "input": "10\n2827343 1373647 96204862 723505 796619138 71550121 799843967 5561265 402690754 446173607", "output": "2" }, { "input": "1...	171	19,558,400	3	20
109	Lucky Sum of Digits	[ "brute force", "implementation" ]	A. Lucky Sum of Digits	2	256	Petya loves lucky numbers. We all know that lucky numbers are the positive integers whose decimal representations contain only the lucky digits 4 and 7. For example, numbers 47, 744, 4 are lucky and 5, 17, 467 are not. Petya wonders eagerly what minimum lucky number has the sum of digits equal to n. Help him cope with the task.	The single line contains an integer n (1<=≤<=n<=≤<=106) — the sum of digits of the required lucky number.	Print on the single line the result — the minimum lucky number, whose sum of digits equals n. If such number does not exist, print -1.	[ "11\n", "10\n" ]	[ "47\n", "-1\n" ]	none	[ { "input": "11", "output": "47" }, { "input": "10", "output": "-1" }, { "input": "64", "output": "4477777777" }, { "input": "1", "output": "-1" }, { "input": "4", "output": "4" }, { "input": "7", "output": "7" }, { "input": "12", "outpu...	468	102,400	3.882809	21
540	Combination Lock	[ "implementation" ]		null	null	Scrooge McDuck keeps his most treasured savings in a home safe with a combination lock. Each time he wants to put there the treasures that he's earned fair and square, he has to open the lock. The combination lock is represented by n rotating disks with digits from 0 to 9 written on them. Scrooge McDuck has to turn some disks so that the combination of digits on the disks forms a secret combination. In one move, he can rotate one disk one digit forwards or backwards. In particular, in one move he can go from digit 0 to digit 9 and vice versa. What minimum number of actions does he need for that?	The first line contains a single integer n (1<=≤<=n<=≤<=1000) — the number of disks on the combination lock. The second line contains a string of n digits — the original state of the disks. The third line contains a string of n digits — Scrooge McDuck's combination that opens the lock.	Print a single integer — the minimum number of moves Scrooge McDuck needs to open the lock.	[ "5\n82195\n64723\n" ]	[ "13\n" ]	In the sample he needs 13 moves: - 1 disk: <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/b8967f65a723782358b93eff9ce69f336817cf70.png" style="max-width: 100.0%;max-height: 100.0%;"/> - 2 disk: <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/07fa58573ece0d32c4d555e498d2b24d2f70f36a.png" style="max-width: 100.0%;max-height: 100.0%;"/> - 3 disk: <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/cc2275d9252aae35a6867c6a5b4ba7596e9a7626.png" style="max-width: 100.0%;max-height: 100.0%;"/> - 4 disk: <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/b100aea470fcaaab4e9529b234ba0d7875943c10.png" style="max-width: 100.0%;max-height: 100.0%;"/> - 5 disk: <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/eb2cbe4324cebca65b85816262a85e473cd65967.png" style="max-width: 100.0%;max-height: 100.0%;"/>	[ { "input": "5\n82195\n64723", "output": "13" }, { "input": "12\n102021090898\n010212908089", "output": "16" }, { "input": "1\n8\n1", "output": "3" }, { "input": "2\n83\n57", "output": "7" }, { "input": "10\n0728592530\n1362615763", "output": "27" }, { ...	0	0	-1	22
3	Shortest path of the king	[ "greedy", "shortest paths" ]	A. Shortest path of the king	1	64	The king is left alone on the chessboard. In spite of this loneliness, he doesn't lose heart, because he has business of national importance. For example, he has to pay an official visit to square t. As the king is not in habit of wasting his time, he wants to get from his current position s to square t in the least number of moves. Help him to do this. In one move the king can get to the square that has a common side or a common vertex with the square the king is currently in (generally there are 8 different squares he can move to).	The first line contains the chessboard coordinates of square s, the second line — of square t. Chessboard coordinates consist of two characters, the first one is a lowercase Latin letter (from a to h), the second one is a digit from 1 to 8.	In the first line print n — minimum number of the king's moves. Then in n lines print the moves themselves. Each move is described with one of the 8: L, R, U, D, LU, LD, RU or RD. L, R, U, D stand respectively for moves left, right, up and down (according to the picture), and 2-letter combinations stand for diagonal moves. If the answer is not unique, print any of them.	[ "a8\nh1\n" ]	[ "7\nRD\nRD\nRD\nRD\nRD\nRD\nRD\n" ]	none	[ { "input": "a8\nh1", "output": "7\nRD\nRD\nRD\nRD\nRD\nRD\nRD" }, { "input": "b2\nb4", "output": "2\nU\nU" }, { "input": "a5\na5", "output": "0" }, { "input": "h1\nb2", "output": "6\nLU\nL\nL\nL\nL\nL" }, { "input": "c5\nh2", "output": "5\nRD\nRD\nRD\nR\nR" ...	184	0	3.908	23
144	Arrival of the General	[ "implementation" ]		null	null	A Ministry for Defense sent a general to inspect the Super Secret Military Squad under the command of the Colonel SuperDuper. Having learned the news, the colonel ordered to all n squad soldiers to line up on the parade ground. By the military charter the soldiers should stand in the order of non-increasing of their height. But as there's virtually no time to do that, the soldiers lined up in the arbitrary order. However, the general is rather short-sighted and he thinks that the soldiers lined up correctly if the first soldier in the line has the maximum height and the last soldier has the minimum height. Please note that the way other solders are positioned does not matter, including the case when there are several soldiers whose height is maximum or minimum. Only the heights of the first and the last soldier are important. For example, the general considers the sequence of heights (4, 3, 4, 2, 1, 1) correct and the sequence (4, 3, 1, 2, 2) wrong. Within one second the colonel can swap any two neighboring soldiers. Help him count the minimum time needed to form a line-up which the general will consider correct.	The first input line contains the only integer n (2<=≤<=n<=≤<=100) which represents the number of soldiers in the line. The second line contains integers a1,<=a2,<=...,<=an (1<=≤<=ai<=≤<=100) the values of the soldiers' heights in the order of soldiers' heights' increasing in the order from the beginning of the line to its end. The numbers are space-separated. Numbers a1,<=a2,<=...,<=an are not necessarily different.	Print the only integer — the minimum number of seconds the colonel will need to form a line-up the general will like.	[ "4\n33 44 11 22\n", "7\n10 10 58 31 63 40 76\n" ]	[ "2\n", "10\n" ]	In the first sample the colonel will need to swap the first and second soldier and then the third and fourth soldier. That will take 2 seconds. The resulting position of the soldiers is (44, 33, 22, 11). In the second sample the colonel may swap the soldiers in the following sequence: 1. (10, 10, 58, 31, 63, 40, 76) 1. (10, 58, 10, 31, 63, 40, 76) 1. (10, 58, 10, 31, 63, 76, 40) 1. (10, 58, 10, 31, 76, 63, 40) 1. (10, 58, 31, 10, 76, 63, 40) 1. (10, 58, 31, 76, 10, 63, 40) 1. (10, 58, 31, 76, 63, 10, 40) 1. (10, 58, 76, 31, 63, 10, 40) 1. (10, 76, 58, 31, 63, 10, 40) 1. (76, 10, 58, 31, 63, 10, 40) 1. (76, 10, 58, 31, 63, 40, 10)	[ { "input": "4\n33 44 11 22", "output": "2" }, { "input": "7\n10 10 58 31 63 40 76", "output": "10" }, { "input": "2\n88 89", "output": "1" }, { "input": "5\n100 95 100 100 88", "output": "0" }, { "input": "7\n48 48 48 48 45 45 45", "output": "0" }, { "...	30	0	-1	24
676	Vasya and String	[ "binary search", "dp", "strings", "two pointers" ]		null	null	High school student Vasya got a string of length n as a birthday present. This string consists of letters 'a' and 'b' only. Vasya denotes beauty of the string as the maximum length of a substring (consecutive subsequence) consisting of equal letters. Vasya can change no more than k characters of the original string. What is the maximum beauty of the string he can achieve?	The first line of the input contains two integers n and k (1<=≤<=n<=≤<=100<=000,<=0<=≤<=k<=≤<=n) — the length of the string and the maximum number of characters to change. The second line contains the string, consisting of letters 'a' and 'b' only.	Print the only integer — the maximum beauty of the string Vasya can achieve by changing no more than k characters.	[ "4 2\nabba\n", "8 1\naabaabaa\n" ]	[ "4\n", "5\n" ]	In the first sample, Vasya can obtain both strings "aaaa" and "bbbb". In the second sample, the optimal answer is obtained with the string "aaaaabaa" or with the string "aabaaaaa".	[ { "input": "4 2\nabba", "output": "4" }, { "input": "8 1\naabaabaa", "output": "5" }, { "input": "1 0\na", "output": "1" }, { "input": "1 1\nb", "output": "1" }, { "input": "1 0\nb", "output": "1" }, { "input": "1 1\na", "output": "1" }, { ...	124	102,400	3	25
955	Feed the cat	[ "greedy", "math" ]		null	null	After waking up at hh:mm, Andrew realised that he had forgotten to feed his only cat for yet another time (guess why there's only one cat). The cat's current hunger level is H points, moreover each minute without food increases his hunger by D points. At any time Andrew can visit the store where tasty buns are sold (you can assume that is doesn't take time to get to the store and back). One such bun costs C roubles and decreases hunger by N points. Since the demand for bakery drops heavily in the evening, there is a special 20% discount for buns starting from 20:00 (note that the cost might become rational). Of course, buns cannot be sold by parts. Determine the minimum amount of money Andrew has to spend in order to feed his cat. The cat is considered fed if its hunger level is less than or equal to zero.	The first line contains two integers hh and mm (00<=≤<=hh<=≤<=23,<=00<=≤<=mm<=≤<=59) — the time of Andrew's awakening. The second line contains four integers H, D, C and N (1<=≤<=H<=≤<=105,<=1<=≤<=D,<=C,<=N<=≤<=102).	Output the minimum amount of money to within three decimal digits. You answer is considered correct, if its absolute or relative error does not exceed 10<=-<=4. Formally, let your answer be a, and the jury's answer be b. Your answer is considered correct if .	[ "19 00\n255 1 100 1\n", "17 41\n1000 6 15 11\n" ]	[ "25200.0000\n", "1365.0000\n" ]	In the first sample Andrew can visit the store at exactly 20:00. The cat's hunger will be equal to 315, hence it will be necessary to purchase 315 buns. The discount makes the final answer 25200 roubles. In the second sample it's optimal to visit the store right after he wakes up. Then he'll have to buy 91 bins per 15 roubles each and spend a total of 1365 roubles.	[ { "input": "19 00\n255 1 100 1", "output": "25200.0000" }, { "input": "17 41\n1000 6 15 11", "output": "1365.0000" }, { "input": "16 34\n61066 14 50 59", "output": "43360.0000" }, { "input": "18 18\n23331 86 87 41", "output": "49590.0000" }, { "input": "10 48\n684...	30	0	0	27
764	Taymyr is calling you	[ "brute force", "implementation", "math" ]		null	null	Comrade Dujikov is busy choosing artists for Timofey's birthday and is recieving calls from Taymyr from Ilia-alpinist. Ilia-alpinist calls every n minutes, i.e. in minutes n, 2n, 3n and so on. Artists come to the comrade every m minutes, i.e. in minutes m, 2m, 3m and so on. The day is z minutes long, i.e. the day consists of minutes 1,<=2,<=...,<=z. How many artists should be killed so that there are no artists in the room when Ilia calls? Consider that a call and a talk with an artist take exactly one minute.	The only string contains three integers — n, m and z (1<=≤<=n,<=m,<=z<=≤<=104).	Print single integer — the minimum number of artists that should be killed so that there are no artists in the room when Ilia calls.	[ "1 1 10\n", "1 2 5\n", "2 3 9\n" ]	[ "10\n", "2\n", "1\n" ]	Taymyr is a place in the north of Russia. In the first test the artists come each minute, as well as the calls, so we need to kill all of them. In the second test we need to kill artists which come on the second and the fourth minutes. In the third test — only the artist which comes on the sixth minute.	[ { "input": "1 1 10", "output": "10" }, { "input": "1 2 5", "output": "2" }, { "input": "2 3 9", "output": "1" }, { "input": "4 8 9", "output": "1" }, { "input": "7 9 2", "output": "0" }, { "input": "10000 10000 10000", "output": "1" }, { "i...	1,000	1,024,000	0	28
525	Vitaliy and Pie	[ "greedy", "hashing", "strings" ]		null	null	After a hard day Vitaly got very hungry and he wants to eat his favorite potato pie. But it's not that simple. Vitaly is in the first room of the house with n room located in a line and numbered starting from one from left to right. You can go from the first room to the second room, from the second room to the third room and so on — you can go from the (n<=-<=1)-th room to the n-th room. Thus, you can go to room x only from room x<=-<=1. The potato pie is located in the n-th room and Vitaly needs to go there. Each pair of consecutive rooms has a door between them. In order to go to room x from room x<=-<=1, you need to open the door between the rooms with the corresponding key. In total the house has several types of doors (represented by uppercase Latin letters) and several types of keys (represented by lowercase Latin letters). The key of type t can open the door of type T if and only if t and T are the same letter, written in different cases. For example, key f can open door F. Each of the first n<=-<=1 rooms contains exactly one key of some type that Vitaly can use to get to next rooms. Once the door is open with some key, Vitaly won't get the key from the keyhole but he will immediately run into the next room. In other words, each key can open no more than one door. Vitaly realizes that he may end up in some room without the key that opens the door to the next room. Before the start his run for the potato pie Vitaly can buy any number of keys of any type that is guaranteed to get to room n. Given the plan of the house, Vitaly wants to know what is the minimum number of keys he needs to buy to surely get to the room n, which has a delicious potato pie. Write a program that will help Vitaly find out this number.	The first line of the input contains a positive integer n (2<=≤<=n<=≤<=105) — the number of rooms in the house. The second line of the input contains string s of length 2·n<=-<=2. Let's number the elements of the string from left to right, starting from one. The odd positions in the given string s contain lowercase Latin letters — the types of the keys that lie in the corresponding rooms. Thus, each odd position i of the given string s contains a lowercase Latin letter — the type of the key that lies in room number (i<=+<=1)<=/<=2. The even positions in the given string contain uppercase Latin letters — the types of doors between the rooms. Thus, each even position i of the given string s contains an uppercase letter — the type of the door that leads from room i<=/<=2 to room i<=/<=2<=+<=1.	Print the only integer — the minimum number of keys that Vitaly needs to buy to surely get from room one to room n.	[ "3\naAbB\n", "4\naBaCaB\n", "5\nxYyXzZaZ\n" ]	[ "0\n", "3\n", "2\n" ]	none	[ { "input": "3\naAbB", "output": "0" }, { "input": "4\naBaCaB", "output": "3" }, { "input": "5\nxYyXzZaZ", "output": "2" }, { "input": "26\naAbBcCdDeEfFgGhHiIjJkKlLmMnNoOpPqQrRsStTuUvVwWxXyY", "output": "0" }, { "input": "26\nzAyBxCwDvEuFtGsHrIqJpKoLnMmNlOkPjQiRhSg...	140	409,600	3	29
915	Permute Digits	[ "dp", "greedy" ]		null	null	You are given two positive integer numbers a and b. Permute (change order) of the digits of a to construct maximal number not exceeding b. No number in input and/or output can start with the digit 0. It is allowed to leave a as it is.	The first line contains integer a (1<=≤<=a<=≤<=1018). The second line contains integer b (1<=≤<=b<=≤<=1018). Numbers don't have leading zeroes. It is guaranteed that answer exists.	Print the maximum possible number that is a permutation of digits of a and is not greater than b. The answer can't have any leading zeroes. It is guaranteed that the answer exists. The number in the output should have exactly the same length as number a. It should be a permutation of digits of a.	[ "123\n222\n", "3921\n10000\n", "4940\n5000\n" ]	[ "213\n", "9321\n", "4940\n" ]	none	[ { "input": "123\n222", "output": "213" }, { "input": "3921\n10000", "output": "9321" }, { "input": "4940\n5000", "output": "4940" }, { "input": "23923472834\n23589234723", "output": "23498743322" }, { "input": "102391019\n491010301", "output": "399211100" },...	62	0	0	30
749	Bachgold Problem	[ "greedy", "implementation", "math", "number theory" ]		null	null	Bachgold problem is very easy to formulate. Given a positive integer n represent it as a sum of maximum possible number of prime numbers. One can prove that such representation exists for any integer greater than 1. Recall that integer k is called prime if it is greater than 1 and has exactly two positive integer divisors — 1 and k.	The only line of the input contains a single integer n (2<=≤<=n<=≤<=100<=000).	The first line of the output contains a single integer k — maximum possible number of primes in representation. The second line should contain k primes with their sum equal to n. You can print them in any order. If there are several optimal solution, print any of them.	[ "5\n", "6\n" ]	[ "2\n2 3\n", "3\n2 2 2\n" ]	none	[ { "input": "5", "output": "2\n2 3" }, { "input": "6", "output": "3\n2 2 2" }, { "input": "2", "output": "1\n2" }, { "input": "3", "output": "1\n3" }, { "input": "99999", "output": "49999\n2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 ...	46	102,400	3	32
204	Little Elephant and Interval	[ "binary search", "combinatorics", "dp" ]		null	null	The Little Elephant very much loves sums on intervals. This time he has a pair of integers l and r (l<=≤<=r). The Little Elephant has to find the number of such integers x (l<=≤<=x<=≤<=r), that the first digit of integer x equals the last one (in decimal notation). For example, such numbers as 101, 477474 or 9 will be included in the answer and 47, 253 or 1020 will not. Help him and count the number of described numbers x for a given pair l and r.	The single line contains a pair of integers l and r (1<=≤<=l<=≤<=r<=≤<=1018) — the boundaries of the interval. Please, do not use the %lld specifier to read or write 64-bit integers in С++. It is preferred to use cin, cout streams or the %I64d specifier.	On a single line print a single integer — the answer to the problem.	[ "2 47\n", "47 1024\n" ]	[ "12\n", "98\n" ]	In the first sample the answer includes integers 2, 3, 4, 5, 6, 7, 8, 9, 11, 22, 33, 44.	[ { "input": "2 47", "output": "12" }, { "input": "47 1024", "output": "98" }, { "input": "1 1000", "output": "108" }, { "input": "1 10000", "output": "1008" }, { "input": "47 8545", "output": "849" }, { "input": "1000 1000", "output": "0" }, { ...	92	0	0	33
294	Shaass and Oskols	[ "implementation", "math" ]		null	null	Shaass has decided to hunt some birds. There are n horizontal electricity wires aligned parallel to each other. Wires are numbered 1 to n from top to bottom. On each wire there are some oskols sitting next to each other. Oskol is the name of a delicious kind of birds in Shaass's territory. Supposed there are ai oskols sitting on the i-th wire. Sometimes Shaass shots one of the birds and the bird dies (suppose that this bird sat at the i-th wire). Consequently all the birds on the i-th wire to the left of the dead bird get scared and jump up on the wire number i<=-<=1, if there exists no upper wire they fly away. Also all the birds to the right of the dead bird jump down on wire number i<=+<=1, if there exists no such wire they fly away. Shaass has shot m birds. You're given the initial number of birds on each wire, tell him how many birds are sitting on each wire after the shots.	The first line of the input contains an integer n, (1<=≤<=n<=≤<=100). The next line contains a list of space-separated integers a1,<=a2,<=...,<=an, (0<=≤<=ai<=≤<=100). The third line contains an integer m, (0<=≤<=m<=≤<=100). Each of the next m lines contains two integers xi and yi. The integers mean that for the i-th time Shaass shoot the yi-th (from left) bird on the xi-th wire, (1<=≤<=xi<=≤<=n,<=1<=≤<=yi). It's guaranteed there will be at least yi birds on the xi-th wire at that moment.	On the i-th line of the output print the number of birds on the i-th wire.	[ "5\n10 10 10 10 10\n5\n2 5\n3 13\n2 12\n1 13\n4 6\n", "3\n2 4 1\n1\n2 2\n" ]	[ "0\n12\n5\n0\n16\n", "3\n0\n3\n" ]	none	[ { "input": "5\n10 10 10 10 10\n5\n2 5\n3 13\n2 12\n1 13\n4 6", "output": "0\n12\n5\n0\n16" }, { "input": "3\n2 4 1\n1\n2 2", "output": "3\n0\n3" }, { "input": "5\n58 51 45 27 48\n5\n4 9\n5 15\n4 5\n5 8\n1 43", "output": "0\n66\n57\n7\n0" }, { "input": "10\n48 53 10 28 91 56 8...	124	0	3	34
0	none	[ "none" ]		null	null	Alice and Bob decided to eat some fruit. In the kitchen they found a large bag of oranges and apples. Alice immediately took an orange for herself, Bob took an apple. To make the process of sharing the remaining fruit more fun, the friends decided to play a game. They put multiple cards and on each one they wrote a letter, either 'A', or the letter 'B'. Then they began to remove the cards one by one from left to right, every time they removed a card with the letter 'A', Alice gave Bob all the fruits she had at that moment and took out of the bag as many apples and as many oranges as she had before. Thus the number of oranges and apples Alice had, did not change. If the card had written letter 'B', then Bob did the same, that is, he gave Alice all the fruit that he had, and took from the bag the same set of fruit. After the last card way removed, all the fruit in the bag were over. You know how many oranges and apples was in the bag at first. Your task is to find any sequence of cards that Alice and Bob could have played with.	The first line of the input contains two integers, x,<=y (1<=≤<=x,<=y<=≤<=1018,<=xy<=><=1) — the number of oranges and apples that were initially in the bag.	Print any sequence of cards that would meet the problem conditions as a compressed string of characters 'A' and 'B. That means that you need to replace the segments of identical consecutive characters by the number of repetitions of the characters and the actual character. For example, string AAABAABBB should be replaced by string 3A1B2A3B, but cannot be replaced by 2A1A1B2A3B or by 3AB2A3B. See the samples for clarifications of the output format. The string that you print should consist of at most 106 characters. It is guaranteed that if the answer exists, its compressed representation exists, consisting of at most 106 characters. If there are several possible answers, you are allowed to print any of them. If the sequence of cards that meet the problem statement does not not exist, print a single word Impossible.	[ "1 4\n", "2 2\n", "3 2\n" ]	[ "3B\n", "Impossible\n", "1A1B\n" ]	In the first sample, if the row contained three cards with letter 'B', then Bob should give one apple to Alice three times. So, in the end of the game Alice has one orange and three apples, and Bob has one apple, in total it is one orange and four apples. In second sample, there is no answer since one card is not enough for game to finish, and two cards will produce at least three apples or three oranges. In the third sample, cards contain letters 'AB', so after removing the first card Bob has one orange and one apple, and after removal of second card Alice has two oranges and one apple. So, in total it is three oranges and two apples.	[ { "input": "1 4", "output": "3B" }, { "input": "2 2", "output": "Impossible" }, { "input": "3 2", "output": "1A1B" }, { "input": "2 1", "output": "1A" }, { "input": "5 3", "output": "1A1B1A" }, { "input": "5 2", "output": "2A1B" }, { "input...	62	0	3	35
80	Panoramix's Prediction	[ "brute force" ]	A. Panoramix's Prediction	2	256	A prime number is a number which has exactly two distinct divisors: one and itself. For example, numbers 2, 7, 3 are prime, and 1, 6, 4 are not. The next prime number after x is the smallest prime number greater than x. For example, the next prime number after 2 is 3, and the next prime number after 3 is 5. Note that there is exactly one next prime number after each number. So 5 is not the next prime number for 2. One cold April morning Panoramix predicted that soon Kakofonix will break free from his straitjacket, and this will be a black day for the residents of the Gallic countryside. Panoramix's prophecy tells that if some day Asterix and Obelix beat exactly x Roman soldiers, where x is a prime number, and next day they beat exactly y Roman soldiers, where y is the next prime number after x, then it's time to wait for Armageddon, for nothing can shut Kakofonix up while he sings his infernal song. Yesterday the Gauls beat n Roman soldiers and it turned out that the number n was prime! Today their victims were a troop of m Romans (m<=><=n). Determine whether the Gauls should wait for the black day after today's victory of Asterix and Obelix?	The first and only input line contains two positive integers — n and m (2<=≤<=n<=<<=m<=≤<=50). It is guaranteed that n is prime. Pretests contain all the cases with restrictions 2<=≤<=n<=<<=m<=≤<=4.	Print YES, if m is the next prime number after n, or NO otherwise.	[ "3 5\n", "7 11\n", "7 9\n" ]	[ "YES", "YES", "NO" ]	none	[ { "input": "3 5", "output": "YES" }, { "input": "7 11", "output": "YES" }, { "input": "7 9", "output": "NO" }, { "input": "2 3", "output": "YES" }, { "input": "2 4", "output": "NO" }, { "input": "3 4", "output": "NO" }, { "input": "3 5", ...	218	6,963,200	3.93253	36

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