#include <bits/stdc++.h>
#define p(s) cout<<(s)<<endl
using namespace std;

int main(){
	string s1,s2,p1,p2,x1,x2;
	cin>>s1>>p1>>x1>>s2>>p2>>x2;
	if(p1.size()>p2.size()) p(s1);
	else if(p1.size()<p2.size()) p(s2);
	else {
		if(p1>p2) p(s1);
		else if(p1<p2) p(s2);
		else p(-1);
	}
	return 0;
}