english-19 Duplicate Number

描述

Given a sequence of N numbers, find a number A that the count of A in the sequence is at least two.

输入

First line: one positive integer N (N <= 1000).Second line: N positive integers (<= 1000000).

输出

One integer A.

样例输入

1
2
38
2 4 2 1 5 3 9 6

样例输出

12

限制

• 时间限制：1000ms
• 内存限制：128MB