BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); while (true) { String str = reader.readLine(); if (str.equals("exit")) break; try { if (str.contains(".")) print(Double.valueOf(str)); else if (Short.valueOf(str) > 0 && Short.valueOf(str) < 128) print(Short.valueOf(str)); else if (Integer.valueOf(str) <= 0 || Integer.valueOf(str) >= 128) print(Integer.valueOf(str)); } catch (NumberFormatException e) { print(str); } } reader.close();