def main():
    a1, b1, c1 = input().split()
    a2, b2, c2 = input().split()
    if int(b1) > int(b2):
        print(a1)
    elif int(b1) < int(b2):
        print(a2)
    else:
        print(-1)


if __name__ == '__main__':
    main()