#include <iostream>
#include <cstdint>

using namespace std;

int main()
{
	cin.tie(nullptr);
	ios::sync_with_stdio(false);

	uint16_t D;
	cin >> D;

	if ((D & 2) == 0) cout << (static_cast<uint32_t>(D >> 2) * (D >> 2)) << '\n';
	else cout << static_cast<uint32_t>(D >> 2) * ((D + 2) >> 2) << '\n';

	return 0;
}