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.
// package com.trivv.training.otp;

import java.io.File;
import java.util.ArrayList;
import java.util.Scanner;

public class ReachableNumber {
	
	private static final String FILE_INPUT = "ReachableNumber.inp";
	private int n;
	private ArrayList<Integer> ffunc = new ArrayList<Integer>();
	
	public void input(String inFile) {
		try {
			// Scanner reader = new Scanner(new File(inFile));
			Scanner reader = new Scanner(System.in);
			n = reader.nextInt();
			//System.out.println("n = " + n);
			reader.close();
		} catch (Exception ex) {
			// TODO Auto-generated catch block
			ex.printStackTrace();
		}
	}
	
	private int removeZero(int n) {
		while (n > 0 && n % 10 == 0) {
			n = n / 10;
		}
		return n;
	}
	
	public void countReachableNumber() {
		// System.out.print("f(" + n + ") > ");
		if (n == 1) {
			System.out.println(9);
			return;
		}
		int m = n;
		int fm = 0;
		int res = 0;
		ffunc.add(m);
		while (true) {
			fm = removeZero(m + 1);
			int index = ffunc.indexOf(fm);
			if (index >= 0) break;
			ffunc.add(fm);
			m = fm;
			// System.out.print("f(" + m + ") > ");
		}
		// f(10) f(11), f(12) 13, 14, 15, 16, 17, 18, 19, 2, 3, 4, 5, 6, 7, 8, 9, 10
		// 1 , 2, 3,4, 5, 6, 7, 8, 9, 1
		// 9 , 
		System.out.println(ffunc.size());
	}
	
	public static void main(String[] args) {
		ReachableNumber runner = new ReachableNumber();
		runner.input(FILE_INPUT);
		runner.countReachableNumber();
	}
}
