#include <iostream>
using namespace std;
int main()
{
	int i,j, X, Y,days;
	days = 0;
	for (i = 1; i <= 12; i++)
	{
		for (j = 1; j <= 31; j++)
		{
			if (X == (Y / 10) + Y)
			{
				days++;
			}
		}
	}
	cout << days-1 << "\n";
	return 0;
}