#include <iostream>
#include <algorithm>
#include <string>
#include <queue>
#include <vector>
#include <map>
#include <cstdio>
#include <cmath>
#define INF 100000000
using namespace std;

int main() {
	int cnt=0;
	for (int i = 1; i <= 12; i++) {
		int day = 31;
		if (i == 2 || i == 4 || i == 6 || i == 9 || i == 11)day--;
		if (i == 2)day -= 2;
		for (int j = 1; j <= day; j++) {
			if (i == (j % 10 + j/10))cnt++;
		}
	}
	cout << cnt << endl;
	return 0;
}