#include <iostream>
using namespace std;


int main() {
	int lastDayOfMonth[] = { 31,28,31,30,31,30,31,31,30,31,30,31 };
	auto answer = 0;
	for (auto month = 0; month != 12; ++month) {
		for (auto day = 1; day != lastDayOfMonth[month] + 1; ++day) {
			if (month + 1 == day / 10 + day % 10) ++answer;
		}
	}
	cout << answer << endl;
	return 0;
}