import java.util.LinkedList;
import java.util.Scanner;
public class Main{
	private static Scanner sc=new Scanner(System.in);
	public static void main(String args[])throws Exception{
		String s=sc.nextLine();
		int sum=0;
		s=s.replaceAll("[^0-9]","");
		LinkedList<Integer>queue=new LinkedList<Integer>();
		for(char element:s.toCharArray()){
			queue.offer(Character.getNumericValue(element));
		}while(queue.isEmpty()==false){
			sum+=queue.removeFirst();
		}System.out.println(sum);
	}
}