#include <iostream>
using namespace std;

int main(void)
{
	int month[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
	int ans = 0;
	for(int i = 1; i <= 12; i++) {
		for(int j = 1; j <= month[i]; j++) {
			if(i == j / 10 + j % 10) {
				ans++;
			}
		}
	}
	cout << ans << endl;
	return 0;
}