#include <iostream>
using namespace std;

enum DayOfWeek {
	Sunday,
	Monday,
	Tuesday,
	Wednesday,
	Thursday,
	Friday,
	Saturday,
};

int Zeller(int y, int m, int d)
{
	if (m < 3) {
		y--; m += 12;
	}
	return (y + y / 4 - y / 100 + y / 400 + (13 * m + 8) / 5 + d) % 7;
}

int main() {
	DayOfWeek day_of_week_table[] = { Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday };

	long long n;
	cin >> n;

	long long num_of_years = n - 2015 + 1;
	long long count = 0;
	
	if (n >= 400) {
		for (int year = 1; year <= 400; year++) {
			if (day_of_week_table[Zeller(year, 7, 23)] == Wednesday)
				count++;
		}
		count *= num_of_years / 400;
	}

	for (int i = 0; i < num_of_years % 400; i++) {
		if (day_of_week_table[Zeller(2015 + i, 7, 23)] == Wednesday)
			count++;
	}

	cout << count << endl;

	return 0;
}