readPort :: ReadM Int
readPort = do
    a <- auto
    guard (a > 0 && a < 65535)
    return a
readPort :: ReadM Int
readPort = do
    a <- auto
    guard (a > 0 && a < 65535)
    return a
readPort = do
    a <- auto
    guard (a > 0 && a < 65535)
    return a