Being unique is so important to people on Mars that even their lottery is designed in a unique way. The rule of winning is simple: one bets on a number chosen from [1, 10⁴]. The first one who bets on a unique number wins. For
example, if there are 7 people betting on 5 31 5 88 67 88 17, then the second one who bets on 31 wins.

Input Specification:

Each input file contains one test case. Each case contains a line which begins with a positive integer N (<=10⁵) and then followed by N bets. The numbers are separated by a space.

Output Specification:

For each test case, print the winning number in a line. If there is no winner, print "None" instead.

Sample Input 1:

7 5 31 5 88 67 88 17

Sample Output 1:

31

Sample Input 2:

5 888 666 666 888 888

Sample Output 2:

None

#include<iostream>

#include<cstdio>

#include<cstring>

#include<string>

#include<algorithm>

#include<cmath>

using namespace std;

int main()

{

	int a[10005],b[100005],n;

while(~scanf("%d",&n))

{

	memset(a,0,sizeof(a));

	for(int i=0;i<n;i++)

	{

		scanf("%d",&b[i]);

		a[b[i]]++;

	}

	int flag=0;

	for(int i=0;i<n;i++)

	{

		if(a[b[i]]<2)

		{

			printf("%d\n",b[i]);

			flag=1;

			break;

		}

	}

	if(!flag)

		printf("None\n");

}

	return 0;

}