import sys
sys.set_int_max_str_digits(20000)


def main():
    S_a, P_a, _ = input().split()
    S_b, P_b, _ = input().split()
    if int(P_a) > int(P_b):
        print(S_a)
    elif int(P_a) < int(P_b):
        print(S_b)
    else:
        print(-1)


if __name__ == "__main__":
    main()