#include <fstream>
using namespace std;
ifstream cin("ciur.in");
ofstream cout("ciur.out");
int main()
{
	int n, s,ok=1;
		cin >> n;
		for (int i = 1; i <= n; i++)
			if (i % 2 != 0 && i % 3 != 0) s++;
		cout << s;

}