#include "bits/stdc++.h"
using namespace std;

int main() {
	int days[13] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, count = 0;
	for (int i = 1; i <= 12; i++) {
		for (int j = 1; j <= days[i]; j++) {
			int j1 = j % 10;
			int j2 = (j - j1) / 10;
			if (i == j1 + j2) count++;
		}
	}
	cout << count << endl;
}