#include<iostream>
#define repi(i,a,b) for(int i=(a);i<(b);++i)

int main()
{
	int N;
	std::cin >> N;

	int ans = 0;
	repi( y, 2015, N+1 ) if( (y+y/4-y/100+y/400+(13*7+8)/5+23)%7 == 3 )
		++ans;

	std::cout << ans << std::endl;

	return 0;
}