SumDigits

using System;

namespace _02SumDigits
{
    class Program
    {
        static void Main(string[] args)
        {
            var input = int.Parse(Console.ReadLine());

            int n = 1;
            double sum = 0;
            while (n > 0)
            {
                n = input;
                sum += n % 10;
                n /= 10;
                input = n;
            }
            Console.WriteLine(sum);
        }
    }
}