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

public class Net {
    public static void main(String[] args) throws IOException {
        DatagramSocket socket = new DatagramSocket(12345);
        boolean running = true;
        byte[] buf = new byte[256];
        System.out.println("Listening on port 12345...");

        while (running) {
            DatagramPacket inPacket  = new DatagramPacket(buf, buf.length);
            socket.receive(inPacket);
            String received = new String(inPacket.getData(), 0, inPacket.getLength());

            if (received.equals("stop")) {
                running = false;
                continue;
            } else {
                System.out.println("Greetings, " + received);
            }
        }
        socket.close();
        System.out.println("end");
    }
}