#include <iostream>
#include <fstream>

using namespace std;

ifstream fin("elmaj.in");
ofstream fout("elmaj.out");

const int NMAX = 1000005;

int v[NMAX];

int main()
{
    int n;
    fin >> n;
    fin >> v[1];
    int culoare,nrbile;
    culoare=v[1];
    nrbile=1;
    for(int i=2;i<=n;i++)
    {
        fin >> v[i];
        if(nrbile==0)
        {
            culoare=v[i];
            nrbile=1;
        }
        else
        {
            if(v[i]==culoare)
            {
                nrbile++;
            }
            else
                nrbile--;
        }
    }
    int k=0;
    for(int i=1;i<=n;i++) if(v[i]==culoare) k++;
    if(k>(n/2)+1) fout << culoare;
    else fout << -1;
    return 0;
}