302480: CF478A. Initial Bet
Memory Limit:256 MB
Time Limit:1 S
Judge Style:Text Compare
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Description
Initial Bet
题意翻译
有五个人在玩游戏 每个人一开始有 $b$ 个硬币 有一种操作是把一个硬币给另一个人 给你所有人经过若干次操作的硬币数 $c[i]$($0\le c[i]\le 100$)求正整数 $b$,若无解输出 $-1$。题目描述
There are five people playing a game called "Generosity". Each person gives some non-zero number of coins $ b $ as an initial bet. After all players make their bets of $ b $ coins, the following operation is repeated for several times: a coin is passed from one player to some other player. Your task is to write a program that can, given the number of coins each player has at the end of the game, determine the size $ b $ of the initial bet or find out that such outcome of the game cannot be obtained for any positive number of coins $ b $ in the initial bet.输入输出格式
输入格式
There are five people playing a game called "Generosity". Each person gives some non-zero number of coins $ b $ as an initial bet. After all players make their bets of $ b $ coins, the following operation is repeated for several times: a coin is passed from one player to some other player. Your task is to write a program that can, given the number of coins each player has at the end of the game, determine the size $ b $ of the initial bet or find out that such outcome of the game cannot be obtained for any positive number of coins $ b $ in the initial bet.
输出格式
Print the only line containing a single positive integer $ b $ — the number of coins in the initial bet of each player. If there is no such value of $ b $ , then print the only value "-1" (quotes for clarity).
输入输出样例
输入样例 #1
2 5 4 0 4
输出样例 #1
3
输入样例 #2
4 5 9 2 1
输出样例 #2
-1