#include<bits/stdc++.h>
using namespace std;

int main(){
  string sa;
  string sb;
  int pa,pb;
  char xa,xb;
  cin>>sa>>pa>>xa;
  cin>>sb>>pb>>xb;
  if(pa<=pb){
    cout<<sb<<endl;
  }else if(pa>=pb){
    cout<<sa<<endl;
  }else{
    cout<<"-1"<<endl;
  }
  return 0;
}