#include <cstdio>
using namespace std;
int a[1000000],i,nr,ct,n,vot,q;
int main()
{freopen("elmaj.in","r",stdin);
 freopen("elmaj.out","w",stdout);
 scanf("%d",&n);
 for(i=1;i<=n;i++)
    scanf("%d",&a[i]);
 q=1;
 vot=1;
 for(i=2;i<=n;i++)
    {if(a[i]==a[q])vot++;
       else vot--;
      if(vot==0){q=i;vot=1;}
    }
 nr=a[q];
 for(i=1;i<=n;i++)
    if(nr==a[i]) ct++;
 if(ct>=n/2+1) printf("%d",nr);
   else printf("-1");
}