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 C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <iostream>
#include <vector>
#include<algorithm>
#include<iomanip>
#include<queue>
using namespace std;
#define rep(i,n) for(int i=1;i<=(int)(n);i++)

int main() {
	string N;
	cin>>N;
	int i = N[0] - '0';
	if(N.size()-1) cout<< i-1+(N.size()-1)*9<<endl;
	else cout<<i<<endl;
	


	
	return 0;
}