Let's denote a function f(x) in such a way: we add 1 to x, then, while there is at least one trailing zero in the resulting number, we remove that zero. For example, 

  * f(599) = 6: 599 + 1 = 600 → 60 → 6; 
  * f(7) = 8: 7 + 1 = 8; 
  * f(9) = 1: 9 + 1 = 10 → 1; 
  * f(10099) = 101: 10099 + 1 = 10100 → 1010 → 101. 



We say that some number y is reachable from x if we can apply function f to x some (possibly zero) times so that we get y as a result. For example, 102 is reachable from 10098 because f(f(f(10098))) = f(f(10099)) = f(101) = 102; and any number is reachable from itself.

You are given a number n; your task is to count how many different numbers are reachable from n.

Input

The first line contains one integer n (1 ≤ n ≤ 10^9).

Output

Print one integer: the number of different numbers that are reachable from n.

Examples

Input


1098


Output


20


Input


10


Output


19

Note

The numbers that are reachable from 1098 are:

1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 16, 17, 18, 19, 1098, 1099.
// Don't place your source in a package

import java.lang.reflect.Array;
import java.math.BigInteger;
import java.util.*;
import java.lang.*;
import java.io.*;



// Please name your class Main
public class Main {
    static FastScanner fs=new FastScanner();
    static class FastScanner {
        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st=new StringTokenizer("");
        public String next() {
            while (!st.hasMoreElements())
                try {
                    st=new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            return st.nextToken();
        }
        int Int() {
            return Integer.parseInt(next());
        }

        long Long() {
            return Long.parseLong(next());
        }

        String Str(){
            return next();
        }
    }


    public static void main (String[] args) throws java.lang.Exception {
        PrintWriter out = new PrintWriter(System.out);


        int T=1;
        for(int t=0;t<T;t++){
            int n=Int();
            Solution sol=new Solution(out);
            sol.solution(n);
        }
        out.flush();

    }


    public static int Int(){
        return fs.Int();
    }
    public static long Long(){
        return fs.Long();
    }
    public static String Str(){
        return fs.Str();
    }

}






class Solution{
    PrintWriter out;
    public Solution(PrintWriter out){
        this.out=out;
    }



    public void solution(int n){
        Set<Integer>set=new HashSet<>();
        set.add(n);
        while(true){
            n++;
            while(n%10==0)n/=10;
            if(set.contains(n))break;
            set.add(n);
        }
        out.println(set.size());
    }





}



/*
                             ;\
                            |' \
         _                  ; : ;
        / `-.              /: : |
       |  ,-.`-.          ,': : |
       \  :  `. `.       ,'-. : |
        \ ;    ;  `-.__,'    `-.|
         \ ;   ;  :::  ,::'`:.  `.
          \ `-. :  `    :.    `.  \
           \   \    ,   ;   ,:    (\
            \   :., :.    ,'o)): ` `-.
           ,/,' ;' ,::"'`.`---'   `.  `-._
         ,/  :  ; '"      `;'          ,--`.
        ;/   :; ;             ,:'     (   ,:)
          ,.,:.    ; ,:.,  ,-._ `.     \""'/
          '::'     `:'`  ,'(  \`._____.-'"'
             ;,   ;  `.  `. `._`-.  \\
             ;:.  ;:       `-._`-.\  \`.
              '`:. :        |' `. `\  ) \
      -hrr-      ` ;:       |    `--\__,'
                   '`      ,'
                        ,-'


                      free bug dog
*/





