#include<iostream>
#include<vector>

int main() {
	std::vector<int> day(13, 0);

	for (int i = 1; i < 13; i++) {
		if (i == 2)day[i] = 28;
		else if (i == 4 || i == 6 || i == 9 || i == 11) day[i] = 30;
		else day[i] = 31;
	}

	int count = 0;
	for (int i = 1; i < 13; i++) {
		for (int j = 1; j <= day[i]; j++) {
			if (i == j % 10 + j / 10) count++;
		}
	}

	std::cout << count << std::endl;
}