#include "bits/stdc++.h"
using namespace std;
#define MAX 999999

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