#include <iostream>
using namespace std;

int main() {
	int m[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
	int counter =0;
	
	for(int i=1; i<=12; i++) {
		int d1,d2;
		for(int j=1; j<=m[i-1]; j++) {
			d1 = j / 10;
			d2 = j % 10;
			if ( i == (d1+d2)) counter++;
		}
	}
	cout << counter << '\n';
	return 0;
}