def get_ip_v4_class(ip_int):
    """Return the letter corresponding to the IP class the ip_int is in."""
    if (ip_int & 0x80000000) == 0x00000000:
        return "A"
    elif (ip_int & 0xC0000000) == 0x80000000:
        return "B"
    elif (ip_int & 0xE0000000) == 0xC0000000:
        return "C"
    elif (ip_int & 0xF0000000) == 0xE0000000:
        return "D"
    else:
        return "E"