#include <iostream>
using namespace std;

int main(){
  string n1,n2,y1,y2;
  char h1,h2;
  cin>>n1>>y1>>h1;
  cin>>n2>>y2>>h2;
  int y1s=y1.size();
  int y2s=y2.size();
  if(y1s>y2s) cout<<n1<<endl;
  else if(y1s<y2s) cout<<n2<<endl;
  else {
    for(int i=0; i<y1s; ++i){
      if(y1[i]>y2[i]){
        cout<<n1<<endl;
        return 0;
      } else if(y1[i]<y2[i]){
        cout<<n2<<endl;
        return 0;
      }
    }
    cout<<-1<<endl;
  }
  return 0;
}