how can i simplify my java code

/* Create a program that prompts the user to enter a password. Display a suitable message for each correct or incorrect attempt made. The user must be given three tries after which the program should terminate. */ import java.util.*; import java.util.Random; import javax.swing.*;

public class PatricHenningspassword

{ public static void main (String [] args) { Scanner kb = new Scanner (System.in); String pass=""; int c = 1; int code=0; String tryer; String out= rev_num();

     while (!pass.equals(out) && c<=3)
     {
        c++;
        System.out.println("password is : "+out);
        System.out.println(" Please enter password");
        pass = kb.next();
        if (pass == null)
           System.exit(0);

        if (pass.equals(out))

        {
           System.out.println("Well Done You Right on Target");  
        }            
        else
        {
           if (c<=2 && !pass.equals(out))
           {   System.out.println("nice try sorry \n \n");
      System.out.println("Enter password its your second last chance!!!!");
              pass = kb.next();
              c++;
              if (pass.equals(out))
              {
                 System.out.println("Well Done You Right on Target");  
              } 
              else
              { if (c==3 && !pass.equals(out))
                {
             System.out.println("nice try sorry last try \n \n");
             System.out.println("Enter password its your last chance!!!!");
                   pass = kb.next();
                   c++;
                 if (pass.equals(out))
                 {
                 System.out.println("Well Done You Right on Target");  
                 } 


                 else 
                 {
                    c++;
                    System.out.println("Access Denied !!!!!!!!!");    

                    System.exit(0);
                 }  

              }           
           }


           }
        }
     }
  }


   public static String rev_num()
  {
    int a=0;int d=0;int g=0;int j=0;
     int b=0;int e=0;int h=0;
     int c=0;int f=0;int i=0;

     int counter=0;

     int starter=0;
     int cot=1;

     for (int y=9;y<2;)
     {
        counter--;
     } 
     for (int z=7;z<=4;)
     {
        z--;
       cot++;

        starter=(int)(Math.random() *counter +1);
     } 
     String outr="";



     a = (int)(Math.random() * 9 +counter);
     b = (int)(Math.random() * 9 +starter);
     c = (int)(Math.random() * 9 +cot);
     d = (int)(Math.random() * 9 +counter);
     e = (int)(Math.random() * 9 +1);
     f = (int)(Math.random() * 9 +starter);
     g = (int)(Math.random() * 9 +cot);
     h = (int)(Math.random() * 9 +counter);
     i = (int)(Math.random() * 9 +starter);
     j = (int)(Math.random() * 9 +cot);

     String k=Integer.toString(a); String l=Integer.toString(b); String m=Integer.toString(c);
     String n=Integer.toString(d); String o=Integer.toString(e); String p=Integer.toString(f);
     String q=Integer.toString(g); String r=Integer.toString(h); String s=Integer.toString(i);
     String t=Integer.toString(i);




     outr=k+l+m+n+o+p+q+r+s+t;
     return outr;
        //cannot return again; illegal 


  }

}