#include<iostream>
int main() {
	int daymax[12] = { 31,28,31,30,31,30,31,31,30,31,30,31 };
	int count = 0;
	for (int i = 1; i<=12; i++) {
		for (int j = 1; j <= daymax[i-1]; j++) {
			int a = j % 10;
			int b = j / 10;
			if (i == (a + b)) {
				count++;
			}
		}
	}
	std::cout << count << std::endl;
	return 0;
}