import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String s = scan.next();
		scan.close();
		int cnt = 0;
		for(int i = 0; i < 9; i++) {
			int k = Integer.parseInt(s.substring(i, i + 1));
			if(k == 0) {
				cnt += 10;
			}else {
				cnt += k;
			}
		}
		System.out.println(cnt);
	}
}