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: Runtime Error)

import java.util.Scanner;
public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		String b = String.valueOf(N);
		int a = 1;
		if(N/10 < 10){
			if(N%10 == 9){
				System.out.println(N/10 + N%10);
			}else if(N/10 >= 1){
				System.out.println(N/10 - 1 + 9);
			}else{
				System.out.println(N);
			}
		}else{
			for(int i = 1; i < b.length(); i++){
				a *= 10;
			}
			if(N%a == a - 1){
				System.out.println(9*(b.length() -1) + N/a);
			}else{
				System.out.println(9*(b.length() - 1) + N/a - 1);
			}
		}
	}
}