1041

#include<iostream>
#include<vector>
using namespace std;
#define N 10010
struct node
{
	int v;
	int p;
};
int main()
{
	

		node A[N] = { 0,0 };
		int n;
		cin >> n;
		int max = 0;
		int ans = -1;
		for (int i = 1; i <= n; i++)
		{
			int a;
			cin >> a;
			A[a].v++;
			if(A[a].v==1)
				A[a].p = i;
			if (a > max)
				max = a;
		}
		int min = n+1;
		for (int i = 1; i <= max; i++)
		{
			if (A[i].v == 1)
			{
				if (A[i].p < min)
				{
					min = A[i].p;
					ans = i;
				}
			}
		}
		if (ans == -1)
			cout << "None" << endl;
		else
			cout << ans << endl;
	
	system("pause");
	return 0;
}