#include <iostream>
#include <sstream>
#include <math.h>
#include <stack>
#include <set>
#include <algorithm>
#include <string>
#include <queue>
#include <stack>
#include <map>
#include <cstdio>
#include <vector>
using namespace std;

#define INF (1 << 30)
#define INFLL (1LL << 60)

int main() {
	string a1,a2,a3;
	string b1,b2,b3;
	cin >> a1 >> a2 >> a3;
	cin >> b1 >> b2 >> b3;
	if(a2.size() > b2.size()){
		cout << a1 << endl;
	}else if(a2.size() < b2.size()){
		cout << b1 << endl;
	}else{
		int a,b;
		bool flag = 0;
		for(int i = 0;i < a2.size();i++){
			a = a2[i];
			b = b2[i];
			if(a > b){
				cout << a1 << endl;
				flag = 1;
				break;
			}else if(a < b){
				cout << b1 << endl;
				flag = 1;
				break;
			}
		}
		if(flag == 0) cout << "-1" << endl;
	}
	return 0;
}