int n;


Scanner input = new Scanner(System.in);


while (true) {
System.out.println("Please enter the number 0.");
n = stdin.netxtInt();
if ( n != 0 ) {
System.out.println("Sorry, that was not the correct number. Please try again.");

    continue;

    else if ( n = 0 ) {

     System.out.println("Yes, that was the correct number!");

    break;
   }
  }
}