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: Wrong Answer)

import java.util.Scanner;

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

        String n = sc.next();
        int len = n.length();
        
        if (n.charAt(0) != '9') {
            int ans = 9 * (len - 1) + (n.charAt(0) - '0' - 1);
            System.out.println(ans);
            return;
        }
        
        int numI = 9;
        for (int i = 1; i < len; i++) {
            if (n.charAt(i) != '9') {
                numI = n.charAt(i-1) - '0';
                break;
            }
        }
        
        int ans = 9 * (len - 1) + numI - 1;
        
        System.out.println(ans);
    }
}