import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;

public class No0289 {
	public static void main(String[] args) {
		try (BufferedReader br = 
				new BufferedReader(new InputStreamReader(System.in))) {
			char[] a = br.readLine().toCharArray();
			int sum = 0 ;

			for(int i =0; i < a.length; i++){
				int code= (int)a[i];
				if(47 < code && code < 58){
					sum += Integer.parseInt(Character.toString(a[i]));
				}
			}
			System.out.println(sum);
		} catch (IOException e) {
			e.printStackTrace();
		}
    }
}