//... 
private void demoInput() { 
 int total = 0; 
 int input = 0; 
 do { 
  System.out.println("Insert an integer (0 to quit): ");
 
  input = s.nextInt();
  total += input; 

  System.out.println("Running total is: " + total); 
 } while(input != 0); 
}
//...