不喜勿喷

#include <iostream>
using namespace std;
int main()
{
	short n, sum = 0;
	cin >> n;
	for(short i = 1; i <= 9; i++){
		short a = 0;
		while(true){
			a = a * 10 + i;
			if(a > n) break;
			sum++;
		}
	}
	cout << sum;
	
	return 0;
}