#include<stdio.h>
#include<map>
using namespace std;

int N,x[1000100];

map<int,int> M;

int main()
{
    freopen("elmaj.in","r",stdin);
    freopen("elmaj.out","w",stdout);
    scanf("%d",&N);
    for(int i=1;i<=N;++i)
    {
        scanf("%d",&x[i]);
        M[x[i]]=M[x[i]]+1;

    }

    for(int i=1;i<=N;++i)
    {

        if(M[x[i]]>N/2)
        {
            printf("%d\n",x[i]);
            return 0;
        }
    }

    printf("%d\n",-1);
    return 0;
}