using System;

public class Program
{
    public static void Main()
    {
        //int num = int.Parse(Console.ReadLine() ?? string.Empty);
        //string[] str = (Console.ReadLine() ?? string.Empty).Trim().Split(' ');
        string str = Console.ReadLine() ?? string.Empty;

        int point = 0;
        for (int i = 0; i < str.Length; i++)
        {
            switch (str[i])
            {
                case '1':
                    point += 1;
                    break;
                case '2':
                    point += 2;
                    break;
                case '3':
                    point += 3;
                    break;
                case '4':
                    point += 4;
                    break;
                case '5':
                    point += 5;
                    break;
                case '6':
                    point += 6;
                    break;
                case '7':
                    point += 7;
                    break;
                case '8':
                    point += 8;
                    break;
                case '9':
                    point += 9;
                    break;
                case '0':
                    point += 10;
                    break;
            }

        }
        Console.WriteLine(point);

    }
}