please include function readLine.

static S readLineHidden() ctex {
  if (get(javax(), 'readLine_reader) == null)
    set(javax(), readLine_reader := new BufferedReader(new InputStreamReader(System.in, "UTF-8")));
  try {
    ret ((BufferedReader) get(javax(), 'readLine_reader)).readLine();
  } finally {
    consoleClearInput();
  }
}