import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.LinkedList;
import java.util.List;


public class Main {
	static List<PrintWriter> list = new LinkedList<PrintWriter>();
	public static void main(String args[]) throws IOException{
		ServerSocket ss = new ServerSocket(9843);
		while(true){
			Socket n = ss.accept();
			final BufferedReader read = new BufferedReader(new InputStreamReader(n.getInputStream()));
			final PrintWriter write = new PrintWriter(n.getOutputStream());
			list.add(write);
			new Thread(){
				public void run(){
					try{
						String str;
						while((str=read.readLine())!=null){
							for(PrintWriter w : list){
								//Broadcast to everyone except the sender
								if(w!=write)w.println(str);
							}
						}
					}catch(Exception e){
						e.printStackTrace();
					}
				}
			}.start();
		}
	}
}