using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Demo {

   class MyApplication {

      static void Main(string[] args) {

         int val, result;
         Calc cal = new Calc();

         val = 789;
         Console.WriteLine("Digit:",val);

         result = cal.addFunc(val);
         Console.WriteLine("Sum of Digits in {0} = {1}", val, result);
         Console.ReadLine();
      }
   }

   class Calc {
      public int addFunc(int val) {
         if (val != 0) {
            return (val % 10 + addFunc(val / 10));
         } else {
            return 0;
         }
      }
   }
}