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.*;
import java.util.*;
import java.lang.*;
import java.math.*;
public final  class Main  {
    public static boolean[] prime;
    public static final class FastScanner {
        BufferedReader br;
        StringTokenizer st;

        public FastScanner() {
            try {
                br = new BufferedReader(new InputStreamReader(System.in));
                st = new StringTokenizer(br.readLine());
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

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

        public String next() {
            if (st.hasMoreTokens()) return st.nextToken();
            try {
                st = new StringTokenizer(br.readLine());
            } catch (Exception e) {
                e.printStackTrace();
            }
            return st.nextToken();
        }

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

        public String nextLine() {
            String line = "";
            if (st.hasMoreTokens()) line = st.nextToken();
            else try {
                return br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            while (st.hasMoreTokens()) line += " " + st.nextToken();
            return line;
        }

        public double nextDouble() {
            return Double.parseDouble(next());
        }
    }
    public static final class MF {
        public static long gcd(long a, long b) {
            long var;
            while (a % b > 0) {
                var = b;
                b = a % b;
                a = var;
            }
            return b;
        }

        public static int nod(long x) {
            int i = 0;
            while (x != 0) {
                i++;
                x = x / 10;
            }
            return i;
        }

        public static int nob(long x) {
            return (int) Math.floor(Math.log(x) / Math.log(2)) + 1;
        }

        public static int[] FastradixSort(int[] f) {
            int[] to = new int[f.length];
            {
                int[] b = new int[65537];
                for (int i = 0; i < f.length; i++) b[1 + (f[i] & 0xffff)]++;
                for (int i = 1; i <= 65536; i++) b[i] += b[i - 1];
                for (int i = 0; i < f.length; i++) to[b[f[i] & 0xffff]++] = f[i];
                int[] d = f;
                f = to;
                to = d;
            }
            {
                int[] b = new int[65537];
                for (int i = 0; i < f.length; i++) b[1 + (f[i] >>> 16)]++;
                for (int i = 1; i <= 65536; i++) b[i] += b[i - 1];
                for (int i = 0; i < f.length; i++) to[b[f[i] >>> 16]++] = f[i];
                int[] d = f;
                f = to;
                to = d;
            }
            return f;
        }

        public static void Primesieve(int n) {
            for (int i = 0; i < n; i++)
                prime[i] = true;
            for (int p = 2; p * p < n; p++) {
                if (prime[p] == true) {
                    for (int i = p * p; i < n; i += p)
                        prime[i] = false;
                }
            }
        }
    }
    public static void main(String args[]) {
        FastScanner sc = new FastScanner();
        PrintWriter pw = new PrintWriter(System.out);
        int n,t=0,i;
        HashSet<Integer> set=new HashSet<Integer>();
        n=sc.nextInt();
        while(true)
        {
            set.add(n);
            t++;
            n++;
            while(n%10==0)
                n/=10;
            if(set.contains(n))
                break;
        }
        pw.println(t);
        pw.flush();
        pw.close();
    }

}