using System;
using System.Collections.Generic;
using System.Linq;

namespace BinaryTree
{

    public static class Program
    {
        public static void Main()
        {
            string S = Console.ReadLine();
            int count = 0;
            foreach(char character in S)
            {
                if ("0123456789".Contains(character))
                {
                    count += int.Parse(character.ToString());
                }
            }
            Console.WriteLine(count);
        }
    }
}