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) {
        Main m = new Main();
    }
    
    public Main(){
        Scanner s = new Scanner(System.in);
        char[] N = s.next().toCharArray();
        int zero = 0;
        for(int i = N.length - 1; i > 0; i--){
            if(zero == 1){
                N[i] = '9';
                zero = 0;
            }else if(N[i] <= '8'){
                N[i] = '9';
            }
            
            if(N[i-1] == '0'){
                zero = 1;
            }else{
                N[i-1] -= 1;
            }
            
            System.out.println(N);
        }
        
        int max = 0;
        for(int i = 0; i < N.length; i++){
            max += N[i] - '0';
        }
        System.out.println(max);
    }
    
}