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CodeForces - 347CIt is so boring in the summer holiday, isn't it? So Alice and Bob have invented a new game to play. The rules are as follows. First, they get a set of n distinct integers. And then the

CodeForces - 255BLittle wwl loves different algorithms. Today he has invented a new algorithm just for you. wwl’s algorithm works with string s, consisting of characters “x” and “y”, and uses two follo

CodeForces - 255Awwl is a beginner bodybuilder. Today the gym coach gave him the training plan. All it had was n integers a1, a2, …, an. These numbers mean that wwl needs to do exactly n exercises toda

yxc loves math lessons very much, so he doesn’t attend them, unlike wwl. But now yxc wants to get a good mark for math. For that Ms. lxh, his ACM teacher, gave him a new task. yxc solved the task immed

yxc loves math lessons very much, so he doesn’t attend them, unlike wwl. But now yxc wants to get a good mark for math. For that Ms. lxh, his ACM teacher, gave him a new task. yxc solved the task immed

CodeForces - 233CJohn Doe started thinking about graphs. After some thought he decided that he wants to paint an undirected graph, containing exactly k cycles of length 3.A cycle of length 3 is an unor

CodeForces - 233BLet's consider equation:x2 + s(x)·x - n = 0, where x, n are positive integers, s(x) is the function, equal to the sum of digits of number x in the decimal number system.You are given

CodeForces - 233AA 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

CodeForces - 148C «Next please», — the princess called and cast an estimating glance at the next groom.The princess intends to choose the most worthy groom, this is, the richest one. Whenever she sees

CodeForces - 148BThe princess is going to escape the dragon's cave, and she needs to plan it carefully.The princess runs at vp miles per hour, and the dragon flies at vd miles per hour. The dragon will

CodeForces - 148A«One dragon. Two dragon. Three dragon», — the princess was counting. She had trouble falling asleep, and she got bored of counting lambs when she was nine.However, just counting dragon

E - New Year Cards CodeForces - 140BAs meticulous Gerald sets the table, Alexander finished another post on Codeforces and begins to respond to New Year greetings from friends. Alexander has n friends,

D - New Year Table CodeForces - 140AGerald is setting the New Year table. The table has the form of a circle; its radius equals R. Gerald invited many guests and is concerned whether the table has enou

B - Canvas Frames CodeForces - 127BNicholas, a painter is going to paint several new canvases. Nicholas is sure that the canvases will turn out so great that each one will need framing and being hung o

Wasted Time 　　CodeForces - 127AMr. Scrooge, a very busy man, decided to count the time he wastes on all sorts of useless stuff to evaluate the lost profit. He has already counted the time he wastes sle

CodeForces - 255Cwwl loves sequences of numbers. Recently, he has discovered a new type of sequences which he called an almost arithmetical progression. A sequence is an almost arithmetical progression