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

namespace PracticeAtCoder
{
    class Program
    {
        static void Main(string[] args)
        {
			
			
			//足し算
			string sC = Console.ReadLine();
			string sCA = "";
			int number;
			int sumA = 0;
			//文字長さまで繰り返し処理
			//sC[i]だとchar型と扱われ、型の違いでError　Foreach を用いて対策など
			for(int i = 0; i<sC.Length;i++){
				sCA =sC[i]+"";
				bool success = int.TryParse(sCA , out number);
				
				if(success){
					 //Console.WriteLine($"Converted'{sCA}'to {number},");
					 sumA = sumA +number;
				}else{
					sCA =sC[i]+"";
					//Console.WriteLine($"Attempted conversion of '{sCA ?? "<null>"}' failed.");
				}
			}
			Console.WriteLine(sumA);
				
			
		}
    }
}