#include<iostream>
#include<string>
using namespace std;
int main() {
	long long n = 0, cnt = 0;
	for (int i = 1; i <= 9; i++) {
		string P = "";
		for (int j = 1; j <= 9; j++) {
			P += ('0' + i);
			if (stoll(P) * 1000000001LL <= n)cnt++;
		}
	}
	cout << cnt << endl;
	return 0;
}