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 Java (OpenJDK 11.0.6) (judge verdict: Wrong Answer)

import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc =new Scanner(System.in);
    String N =sc.next();
    int n =N.length();
    String M[]=N.split("",0);
    int x=0;
    for(int i=0;i<n;i++){
      if(!(M[i].equals("9"))){x=-1;break;}}
    long m =Integer.parseInt(M[0]);
    long ans ;
    if(x==-1){ans=m-1+(n-1)*9;}
    else{ans =m+(n-1)*9;}
    System.out.println(ans);
  }
}