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.InputStream;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.util.Locale;
import java.util.StringTokenizer;

public class Solution {

	private static FastReader in;
	private static PrintStream out;
	private static int n;

	public static void main(String[] args) {
		in = new FastReader();
		out = System.out;
		solve();
	}

	protected static void solve() {
		n = in.nextInt();
		int ret = solveLine();
		out.printf(Locale.ENGLISH, "%d%n", ret);
	}

	private static int solveLine() {
		int ans = 1;
		if (n == 10) return 19;
		if (n < 10) return 9;
		while (n > 0) {
			if (n < 10) return ans + 9;
			int digit = n % 10;
			ans += (9 - digit);
			n /= 10;
		}
		return ans;
	}

	protected static class FastReader {
		BufferedReader br;
		StringTokenizer st;

		public FastReader() {
			this(System.in);
		}

		public FastReader(InputStream in) {
			this(new InputStreamReader(in));
		}

		public FastReader(InputStreamReader in) {
			br = new BufferedReader((in));
		}

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

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

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

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

		String nextLine() {
			String str = "";
			try {
				str = br.readLine();
			} catch (IOException e) {
				e.printStackTrace();
			}
			return str;
		}
	}

}
