using System;
using System.Collections.Generic;
using System.Linq;
using System.IO;
using System.Text;
using static System.Console;
using static System.Math;

namespace CP
{
    class Atria
    {
        static void Main(string[] args)
        {
            string s = ReadLine();
            long ans = 0;
            for (int i = 0; i < s.Length; i++)
            {
                if ('1' <= s[i] && s[i] <= '9')
                {
                    ans += int.Parse(s[i].ToString());
                }
            }
            WriteLine(ans);
        }
    }
}