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.
import sun.reflect.generics.tree.Tree;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import java.util.Scanner;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.TreeSet;

public class Main {
    private static  int f(int x){
        //
        while(x%10==0) x/=10;
        return x;
    }
    public static void main(String[] args)throws IOException{
        Reader.init(System.in);
        int x=Reader.nextInt();
        int ans=0;
        int d=x;
        Set<Integer> S=new TreeSet<>();

        while(true){

            ans++;
            S.add(d);
        //    System.out.println(d+" "+x);
            d=f(d+1);
            if(S.contains(d)) break;

        }
        System.out.println(ans);
    }

}
//
class Reader{
    static BufferedReader reader;
    static StringTokenizer tokenizer;

    static void init(InputStream input){
        reader=new BufferedReader(new InputStreamReader(input));
        tokenizer=new StringTokenizer("");
    }
    //
    static String next()throws IOException{
        while(!tokenizer.hasMoreTokens()){
            tokenizer=new StringTokenizer(reader.readLine());
        }
        return tokenizer.nextToken();
    }
    //
    static int nextInt() throws IOException {return Integer.parseInt(next());}
    static double nextDouble()throws IOException{return Double.parseDouble(next());}
    static long nextLong()throws IOException{return Long.parseLong(next());}
}
