import java.util.Scanner;

public class golf {

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

	s = scanner.nextLine();
	int S = Integer.parseInt(s);
	int total = 0;
	int score;
	for(int i=0;i<9;i++){
	    if((score = S % 10) == 0){
		score = 10;
	    }
	    S /= 10;
	    total += score;
	}
	System.out.println(total);
    }

}