using System;
using System.Linq;

namespace StudyApp
{
    class Program
    {
        static void Main(string[] args)
        {
            string s = Console.ReadLine();
            var result = s.Where(data => char.IsDigit(data))
                .Select(data => int.Parse(data.ToString()))
                .Sum();

            Console.WriteLine(result);
        }
    }
}