In the new year party, everybody will get a "special present".Now it‘s your turn to get your special present, a lot of presents now putting on the desk, and only one of them will be yours.Each present has a card number on it, and your present‘s card number will be the one that different from all the others.For example, there are 5 present, and their card numbers are 1, 2, 3, 2, 1.so your present will be the one with the card number of 3, because 3 is the number that different from all the others.

The input file will consist of several cases.  
Each case will be presented by an integer n (1<=n<=200, and n is odd) at first. Following that, n positive integers will be given in a line. These numbers indicate the card numbers of the presents.n = 0 ends the input.

For each case, output an integer in a line, which is the card number of your present.

5
1 1 3 2 2
3
1 2 1
0

3
2

#include<iostream>
using namespace std;
int main()
{
	int n;
	int ls[201];
	while(cin>>n,n)
	{
		int count[201]={0};
		for(int i=0;i<n;i++)
			cin>>ls[i];
		for(int k=0;k<n;k++)
			for(int j=0;j<n;j++)
				if(ls[k]==ls[j])
					count[k]++;
		for(int m=0;m<n;m++)
			if(count[m]==1)
				cout<<ls[m]<<endl;
	}
	return 0;
}