#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<queue>
#include<stack>
#include<set>
#include<vector>
#include<algorithm>
#include<cmath>
using namespace std;

const int MAXN = 10000+10;
int a[MAXN];
int main()
{
    //freopen("Input.txt","r",stdin);
    int n;
    while(~scanf("%d",&n))
    {
        memset(a,0,sizeof(a));
        int m;
        int res = 0;
        int p;
        for(int i = 0; i < n; i++)
        {
            scanf("%d",&m);
            a[m]++;
            if(a[m] > res)
            {
                res = a[m];
                p = m;
            }
        }
        int flag = 0;
        int sum = 0;
        for(int i = 0; i < 10010;i++)
        {
            if(i == p)
            {
                continue;
            }
            sum += a[i];
        }
        if(sum < res)
        {
            flag = 1;
        }
        if(flag)
        {
            printf("%d\n", p);
        }
        else
        {
            printf("-1\n");
        }
    }
    return 0;
}