import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String s = sc.next();
        System.out.println(ans(s));
    }
    
    static int ans(String s) {
        int num = 0;
        for(int i = 0; i < s.length(); i++) {
            int tmp = s.charAt(i) - '0';
            if(tmp == 0) {
                num += 10;
            } else {
                num += tmp;
            }
        }
        return num;
    }
}