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.
/**
 * @author cplayer on 2018/6/23.
 * @version 1.0
 */

import java.util.*;
import java.io.*;
import java.lang.*;

public class Main {

    public static void main(String[] args) {
        try {
            InputReader in;
            PrintWriter out;
            boolean useOutput = false;
            if (System.getProperty("ONLINE_JUDGE") == null) useOutput = true;
            if (useOutput) {
                FileInputStream fin = new FileInputStream(new File("src/data.in"));
                in = new InputReader(fin);
                FileOutputStream fout = new FileOutputStream(new File("src/data.out"));
                out = new PrintWriter(fout);
            } else {
                InputStream inputStream = System.in;
                in = new InputReader(inputStream);
                OutputStream outputStream = System.out;
                out = new PrintWriter(outputStream);
            }
            Solver solver = new Solver(in, out);
            solver.solve();
            out.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    static class Solver {

        private InputReader cin;
        private PrintWriter cout;

        Solver (InputReader cin, PrintWriter cout) {
            this.cin = cin; this.cout = cout;
        }

        public void solve () {
            try {
                int n = cin.nextInt();
                HashSet<Integer> set = new HashSet<>();
                Queue<Integer> queue = new LinkedList<>();
                queue.clear(); set.clear();
                set.add(n);
                queue.add(n);
                while (!queue.isEmpty()) {
                    int cur = queue.poll();
                    cur = cur + 1;
                    while (cur % 10 == 0) cur /= 10;
                    if (!set.contains(cur)) {
                        set.add(cur);
                        queue.add(cur);
                    }
                }
                // cout.println(set);
                cout.println(set.size());
            } catch (RuntimeException e) {
                e.printStackTrace();
                return;
            } catch (Exception e) {
                e.printStackTrace();
                return;
            }

        }
    }

    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream));
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

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

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

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

    }

}