#include <stdio.h>

int main(void) {
	char Sa[101], Sb[101], Pa[10001], Pb[10001], Xa[2], Xb[2];
	int i, num_a, num_b;
	scanf("%s%s%s", Sa, Pa, Xa);
	scanf("%s%s%s", Sb, Pb, Xb);
	i = 0;
	while(Pa[i] != '\0'){
		i++;
	}
	num_a = i;
	i = 0;
	while(Pb[i] != '\0'){
		i++;
	}
	num_b = i;
	if(num_a > num_b)printf("%s\n", Sa);
	else if(num_a < num_b)printf("%s\n", Sb);
	else{
		for(i = 0;i < num_a;i++){
			if(Pa[i] > Pb[i]){
				printf("%s\n", Sa);
				break;
			}
			else if(Pa[i] < Pb[i]){
				printf("%s\n", Sb);
				break;
			}
		}
		if(i == num_a)printf("-1\n");
	}

    return 0;
}