#include <cstdio>

int main(){
	char SA[100], SB[100];
	char XA, XB;
	unsigned long long int PA, PB;

	scanf("%s %d %c", SA, &PA, &XA);
	scanf("%s %d %c", SB, &PB, &XB);

	if (PA > PB) printf("%s\n", SA);
	else if (PA < PB) printf("%s\n", SB);
	else  printf("-1\n");

	return 0;
}