Problem:
Score : 300 points

Problem Statement

Find the maximum possible sum of the digits (in base 10) of a positive integer not greater than N.

Constraints

1\leq N \leq 10^{16}

N is an integer.

Input

Input is given from Standard Input in the following format:

N

Output

Print the maximum possible sum of the digits (in base 10) of a positive integer not greater than N.

Sample Input 1

100

Sample Output 1

18

For example, the sum of the digits in 99 is 18, which turns out to be the maximum value.

Sample Input 2

9995

Sample Output 2

35

For example, the sum of the digits in 9989 is 35, which turns out to be the maximum value.

Sample Input 3

3141592653589793

Sample Output 3

137

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        String s = sc.nextLine();

        String[] str = s.split("");
        int top = Integer.parseInt(str[0]);
        int ans = 0;

        for (int i = 0; i < str.length; i++) {
            ans += Integer.parseInt(str[i]);
        }

        if (ans < top - 1 + 9 * (str.length - 1)) {
            ans = top - 1 + 9 * (str.length - 1);
        }

        System.out.println(ans);

    }


}