using System;

public class Program

{

    public static void Main()

    {

        string t = Console.ReadLine();

        byte[] t_bytes = new byte[t.Length];

        int output = 0;

        for(int i = 0; i < t.Length; i++)

        {

            t_bytes[i] = (byte)t[i];        

        }           

        foreach(byte v in t_bytes)

        {

            if(v % 2 != 0)

            {

                output += v;

            }

        }

        Console.WriteLine(output);

    }

}