import java.net.*;
import java.io.*;

public class UDPDiscardServer {

  public final static int discardPort = 9;
  static byte[] buffer = new byte[65507];

  public static void main(String[] args) {

    int port;

    try {
      port = Integer.parseInt(args[0]);
    }
    catch (Exception e) {
      port = discardPort;
    }

    try {
      DatagramSocket ds = new DatagramSocket(port);
      while (true) {
        try {
          DatagramPacket dp = new DatagramPacket(buffer, buffer.length);
          ds.receive(dp);
          String s = new String(dp.getData(), 0, 0, dp.getLength());
          System.out.println(dp.getAddress() + " at port " + dp.getPort() + " says " + s);
        }
        catch (IOException e) {
          System.err.println(e);
        }      
       } // end while
    }  // end try
    catch (SocketException se) {
      System.err.println(se);
    }  // end catch

  }  // end main

}