01.7.4.2.DigitsToChart

using System;

class DigitsToChart
{
    static void Main()
    {
        string testInput = Console.ReadLine();
        char[] charArr = testInput.ToCharArray();
        int sum = 0;
        foreach (char ch in charArr)
        {
            int number = (int)Char.GetNumericValue(ch);

            if (number > 0)
            {
                sum = sum + number;
            }

        }
        int rest = sum % 9;

        if (rest == 0 && sum == 0)
        {
            Console.WriteLine(0);
        }
        if (rest == 0 && sum > 0)
        {
            Console.WriteLine(9);
        }
        else if (rest != 0)
        {
            Console.WriteLine(rest);
        }
    }
}