#include <iostream>
#include <string>
using namespace std;

int main(){
   string na,nb,pa,pb,gomi;
   cin >> na >> pa >> gomi >> nb >> pb >> gomi;
   if(pa.size() != pb.size()) cout << (pa.size() > pb.size() ? na : nb) << endl;
   else if(pa != pb) cout << (pa > pb ? na : nb) << endl;
   else cout << -1 << endl;
}