using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("1 задача");

            var n = int.Parse(Console.ReadLine());

            var sum = 0;

​

            do

            {

                sum = sum + (n % 10);

                n = n / 10;

            }

            while (n > 0);

            Console.WriteLine("suma: {0}", sum);

​

    }

}