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

class TCPServer
{
 public static void main(String[] args) throws IOException
    {
  ServerSocket serverSocket = null;
  ServerSocket secondServerSocket = null;
     serverSocket = new ServerSocket(10007);
     secondServerSocket = new ServerSocket(10008);
     Socket clientSocket = null;
     Socket secondClientSocket = null;
     clientSocket = serverSocket.accept();
     secondClientSocket = secondServerSocket.accept();
     PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);
     BufferedReader in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));

     PrintWriter secondOut = new PrintWriter(secondClientSocket.getOutputStream(), true);
     BufferedReader secondIn = new BufferedReader(new InputStreamReader(secondClientSocket.getInputStream()));

     String inputLine, secondInputLine;
     System.out.println("Connection Establisted");
     while ((inputLine = in.readLine()) != null)
     {
      int binary[] = new int[inputLine.length()];

   for (int i = 0; i < inputLine.length(); i++)
   {
    binary[i] = inputLine.charAt(i) - '0';
   }

   boolean isBinary = true;

   for (int i = 0; i < binary.length; i++)
   {
    if (binary[i] < 0 || binary[i] > 1)
    {
     isBinary = false;
    }
   }

   if (inputLine.equals("Bye."))
      {
          break;
      }
   else if (!isBinary)
   {
    System.out.println ("Server: " + inputLine);
    out.println("Needs to be binary code.");
    secondOut.println("Needs to be binary code.");
    isBinary = true;
   }
   else if (binary.length != 11)
   {
    out.println("Your binary message needs to be exactly 11 bits long.");
    secondOut.println("Your binary message needs to be exactly 11 bits long.");
   }
      else
      {
       System.out.println ("Server: " + inputLine);
       if (checkP1(binary) && checkP2(binary) && checkP3(binary) && checkP4(binary))
       {
        out.println("No error detected. The original message is " + binary[0] + binary[1]
           + binary[2] + binary[4] + binary[5] + binary[6] + binary[8]);
        secondOut.println("No error detected. The original message is " + binary[0] + binary[1]
          + binary[2] + binary[4] + binary[5] + binary[6] + binary[8]);
       }
       else
       {
        int problemBit = 0;
        if (!checkP1(binary))
        {
         problemBit += 1;
        }
        if (!checkP2(binary))
        {
         problemBit += 2;
        }
        if (!checkP3(binary))
        {
         problemBit += 4;
        }
        if (!checkP4(binary))
        {
         problemBit += 8;
        }
        out.println("There was an error detected in your hamming code. The error is in bit " +
           problemBit + ".");
        secondOut.println("There was an error detected in your hamming code. The error is in bit " +
          problemBit + ".");
       }
      }
     }

     out.close();
     in.close();
     clientSocket.close();
     serverSocket.close();
     secondOut.close();
     secondIn.close();
     secondClientSocket.close();
     secondServerSocket.close();
    }

 public static boolean checkP1(int binary[])
 {
  boolean parityCheck;
  int count = 0;

  count = binary[10] + binary[8] + binary[6] + binary[4] + binary[2] + binary[0];

  if (count % 2 == 0)
  {
   parityCheck = true;
  }
  else
  {
   parityCheck = false;
  }

  return parityCheck;
 }

 public static boolean checkP2(int binary[])
 {
  boolean parityCheck;
  int count = 0;

  count = binary[9] + binary[8] + binary[5] + binary[4] + binary[1] + binary[0];

  if (count % 2 == 0)
  {
   parityCheck = true;
  }
  else
  {
   parityCheck = false;
  }

  return parityCheck;
 }

 public static boolean checkP3(int binary[])
 {
  boolean parityCheck;
  int count = 0;

  count = binary[7] + binary[6] + binary[5] + binary[4];

  if (count % 2 == 0)
  {
   parityCheck = true;
  }
  else
  {
   parityCheck = false;
  }

  return parityCheck;
 }

 public static boolean checkP4(int binary[])
 {
  boolean parityCheck;
  int count = 0;

  count = binary[3] + binary[2] + binary[1] + binary[0];

  if (count % 2 == 0)
  {
   parityCheck = true;
  }
  else
  {
   parityCheck = false;
  }

  return parityCheck;
 }
}