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.
//https://codeforces.com/problemset/problem/1157/A
import java.util.ArrayList;
import java.util.Scanner;

public class Problem_1157_A {
    private static Scanner scanner = new Scanner(System.in);

    public static void main(String[] args) {


        int n = scanner.nextInt();
        String s = String.valueOf(n);
        int temp = Integer.parseInt(String.valueOf(s.charAt(0)));
        if (n < 10)
            System.out.println(9);
        else {
            int ans = 0;
            ArrayList<Integer> list = new ArrayList<>();
//            System.out.println("temp = " + temp);
//            System.out.println("list = " + list);
            if (n % 10 == 0) {
                list.add(n);
                n++;

            }
            while (n != temp) {
                if (list.contains(n))
                    break;
                if (n % 10 == 0) {
                    while (n % 10 == 0) {
                        n /= 10;
                    }
                }
                if (!list.contains(n))
                    list.add(n);
//                System.out.println("n = " + n);
                n++;
            }

            if (!list.contains(temp))
                list.add(temp);
//            System.out.println("list = " + list);


            System.out.println(list.size());
        }





        scanner.close();
    }
}
