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

public class TcpServer {
	public static void main(String[] args) throws IOException {
		if(args.length<1) {
			System.out.println("Usage: program pornum");
			return;
		}
		int port = Integer.parseInt(args[0]);
		System.out.println("Listenting on port: "+port);
		ServerSocket tcpsock = new ServerSocket(port);
		while(true) {
			try {
				Socket connection = tcpsock.accept();
				System.out.println("Connection from: "+connection.getInetAddress().getHostAddress()+":"+connection.getPort());
				connection.close();
			} catch(Throwable t) {
				t.printStackTrace();
			}
		}
	}
}