#include<iostream>
#include<string.h>
using namespace std;
int main(void)
{
	int i, j=0, len1, len2;
	char name1[110], name2[110], te1[3], te2[3];
	char p1[10010], p2[10010];

	cin >> name1 >> p1 >> te1;
	cin >> name2 >> p2 >> te2;

	len1 = strlen(p1);
	len2 = strlen(p2);
	if (len1 > len2)cout << name1;
	else if (len1 < len2)cout << name2;
	else {
		for (i = 0; i < len1; i++) {
			if (p1[i] > p2[i]) {
				cout << name1 << endl;
				j = 1;
				break;
			}
			else if (p1[i] < p2[i]) {
				cout << name2 << endl;
				j = 1;
				break;
			}
		}
	if(p1[len1-1]==p2[len2-1]&&j==0)cout << -1<<endl;

	}

	return 0;
}