public class IO {

    // The main method here serves just to test the readLn() method.
    public static void main(String [] args) {
        String lineIn = readLn();
        System.out.println(lineIn);
    }

    // This is here just in case a user of this class tries to make an
    // instance of it.  That is not necessary, since everything here is static.
    // But it might be done if a different handle on these methods was desired.
    IO() {
    }

    // read a line of input from standard input
    public static String readLn() {
        //set aside memory for the keyboard input
        byte [] byteArray = new byte[512];
        
        //things which could fail should be enclosed
        // in a try/catch statement
        try {
            // read stdin into the byte array.
            System.in.read(byteArray);
        } catch (Exception e) {
            // if there is a failure, print an error
            e.printStackTrace();
        }
        
        //make a String from the array of bytes
        String result = new String(byteArray);

        //check for a return character, and only
        //keep the characters up to the return
        int newLineIndex = result.indexOf("\n");
        result = result.substring(0,newLineIndex);
        
        return result;
    }

   public static String readLn(String prompt) {
      System.out.print(prompt);
      return readLn();
   }
}