Thread: Whats wrong with my looping?

import java.io.*;
   public class dowhile
   {
      public static void main(String[] args)
      {
 
       int START = 0;
       int END = 0;
       int STEP = 0;
       String input = "";
       char a = 'y';
 
               BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
 
 
 
 
  do{     
 
   try{
         System.out.print("Input Starting number: ");
         input = in.readLine();
         START = Integer.parseInt(input);
 
         System.out.print("Input Ending number: ");
         input = in.readLine();
         END = Integer.parseInt(input);
 
         System.out.print("Input Step (interval): ");
         input = in.readLine();
         STEP = Integer.parseInt(input);
      }catch(IOException e)
       {System.out.println("Error");}
 
 
    if( START >= END )
    System.out.println("Starting Should be lesser than the ending number");
 
    if( STEP < 1 )
    System.out.println("Step should be greater than 0");
 
     do{
      System.out.println( START );
 
       START = START + STEP;
 
     }while( START < END && STEP > 0);
 
     try{
     System.out.print("Try again? Y/N: ");
     input = in.readLine();
     a = input.charAt(0); }
     catch(IOException e)
    {System.out.println("Error");}
 
     if(a != 'y' || a != 'Y' || a != 'n' || a != 'N'){
     do{ System.out.println("Enter Y or N only");  
     try{
     System.out.print("Try again? Y/N: ");
     input = in.readLine();
     a = input.charAt(0); }
     catch(IOException e)
    {System.out.println("Error");}
     }while(a != 'y' || a != 'Y' || a != 'n' || a != 'N');}
 
 
 
 
    }while(a == 'y' || a == 'Y');
 
 
}
}

Its been driving me carzy help pls

What are the expected outputs, and what outputs are you actually getting?