int(input("Enter the four components of an IP address"))
is_valid_ip (a1, a2, a3, a4):
    if a1 >= 1 and a1 <= 255 and a2 >= 0 and a2 <= 255 and a3 >= 0 and a3 <= 255 and a4 >= 0 and a4 <= 255:
        return false