using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace yukicoder_289
{
    class Program
    {
        static void Main(string[] args)
        {
            char[] s = Console.ReadLine().ToCharArray();
            int sum = 0;
            for (int i = 0; i < s.Length; i++)
            {
                if (char.IsDigit(s[i]))
                {
                    sum += int.Parse(s[i].ToString());
                }
                
            }
            Console.WriteLine(sum);
            Console.ReadLine();
        }
    }
}