import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;

public class socket {
    public static void main(String arg[]) throws IOException, ClassNotFoundException {
        ServerSocket server_socket = new ServerSocket(500);
        Scanner input = new Scanner(System.in);
        while(true) {
            Socket connection = server_socket.accept();
            System.out.println();
            ObjectOutputStream out  = new ObjectOutputStream(connection.getOutputStream());
            ObjectInputStream in = new ObjectInputStream(connection.getInputStream());

            String message = (String) in.readObject();
            System.out.println(message);
            out.writeObject(input.next());
            out.flush();
            connection.close();
        }
        //DatagramSocket socket = new DatagramSocket(992);
        /*while(true) {
            byte[] rec_data = new byte[512];
            DatagramPacket rec_packet = new DatagramPacket(rec_data,rec_data.length);
            server_socket.accept();
            System.out.println(rec_packet.getData());
            InetAddress address = rec_packet.getAddress();
            int port = rec_packet.getPort();
            DatagramPacket packet = new DatagramPacket(rec_packet.getData(),rec_packet.getLength(),address,port);

        }*/

    }
}