#include <iostream>
#include <cstdio>
using namespace std;
int main()
{
    freopen("elmaj.in","r",stdin);
    freopen("elmaj.out","w",stdout);
    int n,c=0,nr,cc=-1;
    cin>>n;
    for(int i=0;i<n;i++)
    {
        cin>>nr;
        if(cc==-1) cc=nr;
        if(cc==nr) {c++;}
        else c--;
        if(c==0){c=1; cc=nr;}
    }
    c=0;
    for(int i=0;i<n;i++)
    {
        if(cc==nr) c++;
    }
    if(c>((n/2)+1)) cout<<cc;
    else cout<<-1;
    return 0;
}