using System;

public class Hello
{
    public static void Main()
    {
        var s = Console.ReadLine().Trim();
        var ans = 0;
        for (int i = 0; i < 9; i++)
        {
            var w = (int)s[i] - (int)'0';
            ans += w == 0 ? 10 : w;
        }
        Console.WriteLine(ans);
    }
}