#include <fstream>
int main()
{
	unsigned n, x=0, j = 0, a[500000] = {};
	std::ifstream f("fractii.in");
	std::ofstream g("fractii.out");
	f >> n;
	f.close();
	for (unsigned i = 2; i <= n / 2; i++)
	if (!(a[i]))
	{
		for (unsigned o = i * 2; o <= n / 2; a[o] = 1,o+=i);
		a[j++]=i;
	}
    for (unsigned i = 2; i < n; i++)
	for (unsigned u = i + 1; u <= n; u++)
	{
		unsigned l,c=0;
		for (l = 0; l < j; l++)
		if (!(i%a[l]) && !(u%a[l]))
		{
			c = 1; break;
		}
		x += 2 * (!c);
	}
	g <<  x+1+2*(n-1);
	g.close();
}