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

int main(){
  string A1,A2,B1,B2,C1,C2;
  cin>>A1>>B1>>C1;
  cin>>A2>>B2>>C2;
  if(B1.length()>B2.length()){
    cout<<A1<<endl;
    return 0;
  }
  if(B1.length()<B2.length()){
    cout<<A2<<endl;
    return 0;
  }
  for(int i=0;i<B1.length();i++){
    if(B1.at(i)>B2.at(i)){
      cout<<A1<<endl;
      return 0;
    }
    else if(B1.at(i)<B2.at(i)){
      cout<<A2<<endl;
      return 0;
    }
    else{
      continue;
    }
  }
  cout<<-1<<endl;
  return 0;
}