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

int main(){
	string sa,sb,pa,pb,ja,jb;
	cin>>sa>>pa>>ja;
	cin>>sb>>pb>>jb;
	if(pa>pb) cout << sa << endl;
	else if(pa<pb) cout << sb << endl;
	else cout << "-1" << endl;
}