import java.util.*;

public class Main{

  public static void main(String[] args) {

    Scanner sc = new Scanner(System.in);
    String s = sc.nextLine();
    int result =0;
    for (int i=0;i<9 ;i++ ) {
      int k = Integer.parseInt(s.substring(i,i+1));
      if (k==0) {
        result+=10;
      }else {
        result+=k;
      }

    }
System.out.println(result);

  }
}