#include <iostream>
#include <fstream>         // 1 2 2 3 2 2 2 4 2 4 2 4
using namespace std;
int main()
{
    int n, szam, major = 0, db = 0;

    ifstream f("elmaj.in");
    ofstream g("elmaj.out");

    //cin >> n;
    f >> n;

    while(n)
    {
        f >> szam;
        if(db == 0)
        {
            major = szam;
            db = 1;
        }
        else if(major == szam)
            db++;
        else
            db--;
        n--;
    }
    f.close();
    ifstream text("elmaj.in");
    text >> n;
    db = 0;
    for(int i=1; i<=n; i++)
    {
        text>>szam;
        if(szam == major)
            db++;
    }
    if(db > n/2)
    {
        //cout << major;
        g << major;
    }
    else
    {
        //cout << -1;
        g << -1;
    }
    g << '\n';
    return 0;
}