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.BufferedOutputStream;
import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.math.BigInteger;
import java.io.*;
import java.util.*;
public class Main {
	private static Reader fr;
	private static OutputStream out;
	private static final int delta = (int) 1e9 + 7;

	private static class Reader {
		final private int BUFFER_SIZE = 1 << 16;
		private DataInputStream din;
		private byte[] buffer;
		private int bufferPointer, bytesRead;

		public Reader() {
			din = new DataInputStream(System.in);
			buffer = new byte[BUFFER_SIZE];
			bufferPointer = bytesRead = 0;
		}

		public Reader(String file_name) throws IOException {
			din = new DataInputStream(new FileInputStream(file_name));
			buffer = new byte[BUFFER_SIZE];
			bufferPointer = bytesRead = 0;
		}

		public String readLine() throws IOException {
			byte[] buf = new byte[1024];
			int cnt = 0, c;
			while ((c = read()) != -1) {
				if (c == '\n')
					break;
				buf[cnt++] = (byte) c;
			}
			return new String(buf, 0, cnt);
		}

		public int nextInt() throws IOException {
			int ret = 0;
			byte c = read();
			while (c <= ' ')
				c = read();
			boolean neg = (c == '-');
			if (neg)
				c = read();
			do {
				ret = ret * 10 + c - '0';
			} while ((c = read()) >= '0' && c <= '9');

			if (neg)
				return -ret;
			return ret;
		}

		public long nextLong() throws IOException {
			long ret = 0;
			byte c = read();
			while (c <= ' ')
				c = read();
			boolean neg = (c == '-');
			if (neg)
				c = read();
			do {
				ret = ret * 10 + c - '0';
			} while ((c = read()) >= '0' && c <= '9');
			if (neg)
				return -ret;
			return ret;
		}

		public double nextDouble() throws IOException {
			double ret = 0, div = 1;
			byte c = read();
			while (c <= ' ')
				c = read();
			boolean neg = (c == '-');
			if (neg)
				c = read();

			do {
				ret = ret * 10 + c - '0';
			} while ((c = read()) >= '0' && c <= '9');

			if (c == '.') {
				while ((c = read()) >= '0' && c <= '9') {
					ret += (c - '0') / (div *= 10);
				}
			}

			if (neg)
				return -ret;
			return ret;
		}

		private void fillBuffer() throws IOException {
			bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
			if (bytesRead == -1)
				buffer[0] = -1;
		}

		private byte read() throws IOException {
			if (bufferPointer == bytesRead)
				fillBuffer();
			return buffer[bufferPointer++];
		}

		public void close() throws IOException {
			if (din == null)
				return;
			din.close();
		}

		public int[] nextArray(int n) throws IOException {
			int arr[] = new int[n];
			for (int i = 0; i < n; i++) {
				arr[i] = nextInt();
			}
			return arr;
		}
	}

	private static void print(Object str) {
		try {
			out.write(str.toString().getBytes());
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	private static void println(Object str) {
		try {
			out.write((str.toString() + "\n").getBytes());
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	private static void printArray(int arr[]) {
		for (int val : arr) {
			print(val + " ");
		}
		println("");
	}

	private static long add(long a, long b) {
		return add(a, b, delta);
	}

	private static long add(long a, long b, long mod) {
		return ((a % mod) + (b % mod)) % mod;
	}

	private static long multiply(long a, long b) {
		return ((a % delta) * (b % delta)) % delta;
	}

	public static double multiply(double a, double b) {
		return ((a % delta) * (b % delta)) % delta;
	}

	private static long pow(int base, int pow) {
		if (pow == 0)
			return 1;
		if (pow == 1)
			return base;
		long halfPow = pow(base, pow / 2);
		if ((pow & 1) == 0)
			return multiply(halfPow, halfPow);
		return multiply(halfPow, multiply(base, halfPow));
	}

	private static long gcd(long a, long b) {
		if (a == 0 || b == 0)
			return a == 0 ? b : a;
		return gcd(b, a % b);
	}

	private static long kadane(int[] arr) {
		int size = arr.length;
		long max_so_far = Integer.MIN_VALUE, max_ending_here = 0;

		for (int anArr : arr) {
			max_ending_here = max_ending_here + anArr;
			if (max_so_far < max_ending_here)
				max_so_far = max_ending_here;
			if (max_ending_here < 0)
				max_ending_here = 0;
		}
		return max_so_far;
	}

	public static void main(String args[]) throws IOException {
		run();
	}

	private static void run() throws IOException {
		fr = new Reader();
		out = new BufferedOutputStream(System.out);
		solve();
		out.flush();
		out.close();
	}
	static int mod=1000000007;
	private static void solve() throws IOException 
	{
		int t =1;// fr.nextInt();
		for(int t0=1;t0<=t;t0++)
		{
			int n = fr.nextInt();
			int c=1;
			int a[]=new int[11];
		    if(n<10)
		        ++a[n];
			while(true)
			{
			    n++;
			    while(n%10==0)
			        n/=10;
			    if(n<11&&a[n]>0)
			        break;
			    if(n<10)
			        ++a[n];
			    c++;
			}
			System.out.println(c);
		}
    }
}