package m.shin;
import java.util.Scanner;
public class Con656 {

	public static void main(String[] args) {
		Scanner s = new Scanner(System.in);
		String score = s.next();
		s.close();

		int count = 0;
		for(int i = 0;i < 9;i++){
			int k = Integer.parseInt(score.substring(i, i+1));
			if(k == 0){
				count += 10;
			}else{
				count += k;
			}
		}
		System.out.println(count);

	}

}