Why do I've to type a letter in order to connect with a server

When I try to connect my client socket with a server I've to type a letter while it should connect automatically. The server is already made and works as it should without the client. When I type the letter it works but it should connect automaticallly.

import java.io.*; 
import java.net.*; 
import java.util.Scanner;

public class TCPClient {

public static void main(String[] args) throws IOException {
    Scanner scan = new Scanner(System.in);
    String input=scan.next(); 
    String text; 
    BufferedReader inFromUser;
    Socket clientSocket;

    inFromUser = new BufferedReader(new InputStreamReader(System.in)); 

    clientSocket = new Socket("HH-PC", 4567); 

    DataOutputStream outToServer = new DataOutputStream(clientSocket.getOutputStream());
    BufferedReader inFromServer = new BufferedReader(new         InputStreamReader(clientSocket.getInputStream())); 

    while(true) {
        input = scan.next();
        if(input.equals("T")){
            outToServer.writeBytes("T\r\n");
            System.out.println(inFromServer.readLine());
        }
        else if(input.equals("S")){
            outToServer.writeBytes("S\r\n");
            System.out.println(inFromServer.readLine());
        }
        else if(input.equals("Z")){
            outToServer.writeBytes("Z\r\n");
            System.out.println(inFromServer.readLine());
        }
        else if(input.equals("D")){
            System.out.println("Write a message");
            text=inFromUser.readLine();
            outToServer.writeBytes("D "+text + "\r\n");
            System.out.println(inFromServer.readLine());
        }
        else if(input.equals("DW")){
            outToServer.writeBytes("DW\r\n");
            System.out.println(inFromServer.readLine());
        }
        else if(input.equals("Q")){
            clientSocket.close();
            System.out.println("The server is disconnected");
            break;
        }

    } 
}

}