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 java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;

public class Main {
	public static int f(int x) {
		String ans = String.valueOf(x + 1);
		int j = ans.length();
		while(j >= 0) {
			if(ans.charAt(j - 1) != '0')
				break;
			j --;
		}
		return Integer.parseInt(ans.substring(0, j));
	}
	public static void main(String[] args) throws Exception {
		FastReader in = new FastReader();
		int n = in.nextInt();
		TreeSet <Integer> set = new TreeSet <> ();
		set.add(n);
		while(!set.contains(f(n))) 
			set.add(n = f(n));
		System.out.println(set.size());
	}
}

class FastReader {
    BufferedReader br;
    StringTokenizer st;

    public FastReader() {
        br = new BufferedReader(new InputStreamReader(System.in));
    }
    
    public String next() {
        while (st == null || !st.hasMoreElements()) {
            try {
                st = new StringTokenizer(br.readLine());
            } catch (IOException  e) {
                e.printStackTrace();
            }
        }
        return st.nextToken();
    }

    public int nextInt() {
        return Integer.parseInt(next());
    }

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

    public double nextDouble() {
        return Double.parseDouble(next());
    }

    public String nextLine() {
        String str = "";
        try {
            str = br.readLine();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return str;
    }
    
    public int[] nextIntArray(int n) {
    	int[] a = new int[n];
    	for(int i = 0; i < n; i ++)
    		a[i] = nextInt();
    	return a;
    }
    
    public long[] nextLongArray(int n) {
    	long[] a = new long[n];
    	for(int i = 0; i < n; i ++)
    		a[i] = nextLong();
    	return a;
    }
    
    public double[] nextDoubleArray(int n) {
    	double[] a = new double[n];
    	for(int i = 0; i < n; i ++)
    		a[i] = nextDouble();
    	return a;
    }
}