import java.io.*;

class N656{
    public static void main(String args[])throws IOException  {

      String in;

      InputStreamReader is = new InputStreamReader(System.in);       //（１）
      BufferedReader br = new BufferedReader(is);                    //（２）
      in = br.readLine();

      int sum = 0;
      for(int i = 0; i < 9; i++){
        String c = in.substring(i,i+1);

        if(c.equals("0")){
          sum += 10;
        }else{
          sum += Integer.parseInt(c);
        }
      }
      System.out.println(sum);
    }
}