#include<iostream>
#include<algorithm>

using namespace std;

struct person
{
	string name;
	string yuruhuwa;
	string hand;
};
int main()
{
	person player[2];
	for(auto &p : player)
	{
		cin >> p.name >> p.yuruhuwa >> p.hand;
	}
	if(player[0].yuruhuwa==player[1].yuruhuwa){
		cout << "-1" << endl;
		return 0;
	}
	person win = max(player[0],player[1],
		[](const person& a,const person& b){
			return 
				a.yuruhuwa.length()<b.yuruhuwa.length()||
			a.yuruhuwa.length()==b.yuruhuwa.length()&&
				a.yuruhuwa<b.yuruhuwa;
		}
	);
	cout << win.name << endl;
}