using System;

class Program
{
    static void Main(string[] args)
    {
        var input = Console.ReadLine().ToCharArray();
        int score = 0;
        for (int i=0; i < input.Length; i++)
        {
            if (input[i] == '0') score += 10;
            else score += int.Parse(input[i].ToString());       
        }
        Console.WriteLine(score);
    }
}