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.io.PrintWriter;
import java.util.HashSet;
import java.util.Set;
import java.util.StringTokenizer;

public class TaskF {
    private static final String filenameIn = "input.txt";
    private static final String filenameOut = "output.txt";

    // THIS IS SOLUTION!!!!!!!
    // LOOK HERE!
    // HACK ME PLEASE, if you can!!!


    void solve() {
        int n = nextInt();
        Set<Integer> set = new HashSet<>();
        for (int i = 1; i < 10; i++) {
            set.add(i);
        }
        f(n, set);
        System.out.println(set.size());
    }

    void f(int x, Set<Integer> set) {
        set.add(x++);
        while (x % 10 == 0) {
            x /= 10;
        }

        if (x < 10) {
            return;
        }

        f(x, set);
    }


    /**
     * ШАБЛОН
     */

    public static void main(String[] args) {
        new TaskF().run();
    }

    void init() {
        in = new BufferedReader(new InputStreamReader(System.in));
        out = new PrintWriter(System.out);
    }

    void run() {
        try {
            long timeStart = System.currentTimeMillis();

            init();
            solve();

            out.close();

            long timeEnd = System.currentTimeMillis();
            System.err.println("Time = " + (timeEnd - timeStart));
        } catch (Exception e) {
            e.printStackTrace();
            System.exit(-1);
        }
    }

    /**
     * FAST_SCANNER
     */

    static final boolean ONLINE_JUDGE = System.getProperty("ONLINE_JUDGE") != null;

    BufferedReader in;
    PrintWriter out;
    StringTokenizer st;

    String nextLine() {
        try {
            return in.readLine();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

    private String delimiter = " ";

    String next() {
        while (st == null || !st.hasMoreTokens()) {
            try {
                st = new StringTokenizer(in.readLine());
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        return st.nextToken(delimiter);
    }

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

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

    int[] nextIntArray(int n) {
        int[] a = new int[n];
        for (int i = 0; i < n; i++) {
            a[i] = nextInt();
        }
        return a;
    }

    int[][] nextIntMatrix(int n, int m) {
        int[][] a = new int[n][m];
        for (int i = 0; i < n; i++) {
            a[i] = nextIntArray(m);
        }
        return a;
    }

    int getMaxArray(int[] a) {
        int max = Integer.MIN_VALUE;
        for (int x : a) {
            max = Math.max(max, x);
        }
        return max;
    }

    private void setDelimiter(String delimiter) {
        this.delimiter = delimiter;
    }

}
