You are given an array aa consisting of nn integers. In one move, you can choose two indices 1≤i,j≤n1≤i,j≤n such that i≠ji≠j and set ai:=ajai:=aj . You can perform such moves any number of times (possibly, zero). You can choose different indices in d…

Brain's Photos 题目链接: http://codeforces.com/contest/707/problem/A Description 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 becom…

C. Efim and Strange Grade 题目连接: http://codeforces.com/contest/719/problem/C Description Efim just received his grade for the last test. He studies in a special school and his grade can be equal to any positive decimal fraction. First he got disappoin…

A. Whose sentence is it? Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/312/problem/A Description One day, liouzhou_101 got a chat record of Freda and Rainbow. Out of curiosity, he wanted to know which sentences were said…

A. Vitya in the Countryside 题目连接: http://codeforces.com/contest/719/problem/A Description Every summer Vitya comes to visit his grandmother in the countryside. This summer, he got a huge wart. Every grandma knows that one should treat warts when the…

A. Meeting of Old Friends 题目连接: http://codeforces.com/contest/714/problem/A Description 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 s…

B. Vanya and Food Processor 题目连接: http://www.codeforces.com/contest/677/problem/B Description Vanya smashes potato in a vertical food processor. At each moment of time the height of the potato in the processor doesn't exceed h and the processor smash…

B. Case of Fake Numbers Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/556/problem/B Description Andrewid the Android is a galaxy-famous detective. He is now investigating a case of frauds who make fake copies of the famou…

B. Ohana Cleans Up Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/554/problem/B Description Ohana Matsumae is trying to clean a room, which is divided up into an n by n grid of squares. Each square is initially either clea…

A. Kyoya and Photobooks Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/554/problem/A Description Kyoya Ootori is selling photobooks of the Ouran High School Host Club. He has 26 photos, labeled "a" to "z", a…