练习专区
今天的一小步就是明天的一大步
Problem 1099 csj开始挑战英语了
Accepted: 8
Total Submit: 26
Time Limit: 1000ms
Memory Limit: 30720KB
Description
An array of length n, with address from 1 to n inclusive, contains entries from the set {1,2,...,n-1} and there's exactly two elements with the same value. Your task is to find out the value.
Input
Input contains several cases.
Each case includes a number n (1＜n＜=10^4), which is followed by n integers.
The input is ended up with the end of file.
Output
Your must output the value for each case, one per line.
Sample Input
Sample Output
Hint