import java.util.*;
import java.util.stream.Stream;
import java.time.*;
import java.time.format.*;

public class No656 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
		String s = sc.next();
        int total = 0;
        for(int i = 0; i < 9; i++) {
            if(s.charAt(i) != '0') {
                total += Character.getNumericValue(s.charAt(i));
            }else {
                total += 10;
            }
        }
        System.out.println(total);
	}
}