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

class TCPServer {
   public static void main(String argv[]) throws Exception
      {
         String clientSentence;
         String capitalizedSentence;

         ServerSocket welcomeSocket = new ServerSocket(6789);

         while(true) {

            Socket connectionSocket = welcomeSocket.accept();

            BufferedReader inFromClient =
               new BufferedReader(new InputStreamReader(
                  connectionSocket.getInputStream()));

            DataOutputStream outToClient =
               new DataOutputStream(
                  connectionSocket.getOutputStream());

            clientSentence = inFromClient.readLine();

            while(clientSentence != null) {
               capitalizedSentence = 
                     clientSentence.toUpperCase() + '\n';

               outToClient.writeBytes(capitalizedSentence);
               clientSentence = inFromClient.readLine();
            }
            connectionSocket.close();
         }
      }
}