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

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