import java.net.Socket;
import java.net.ServerSocket;
import java.io.IOException;
import java.util.Map;
import java.util.HashMap;
import java.util.Random;
import java.io.ObjectOutputStream;

public class SerialS {
    public static void main (String[] args) {
	try {
	    ServerSocket ssock = new ServerSocket (port);

	    Map<Integer,String> map = new HashMap<Integer,String>();
	    Random r = new Random();

	    while (true) {
		map.clear();
		Socket sock = ssock.accept(); // accept() blocks

		int how_many = Math.abs(r.nextInt()) % 5; // rand [0..4]
		for (int i = 0; i < how_many; i++) {
		    int n = r.nextInt();
		    map.put (new Integer(n), Integer.toHexString(n));
		}
		System.out.println(map);

		ObjectOutputStream out = new ObjectOutputStream (sock.getOutputStream());
		out.writeObject (map);
		out.flush();
	 
		sock.close();
	    }
	}
	catch (IOException e) {
	    System.err.println (e);
	}
    }

    private static final int port = 9876;
}