#include <iostream>
#include <vector>
using namespace std;
int main(void) {
	vector<int> m = { 31,28,31,30,31,30,31,31,30,31,30,31 };
	int cnt = 0;
	for (int i = 0; i < 12; ++i) {
		int month = i + 1;
		for (int j = 0; j < m[i]; ++j) {
			int day = j + 1;
			int sum = day / 10 + day % 10;
			if (month == sum) ++cnt;
		}
	}
	cout << cnt << endl;
	return 0;
}