#include #define fastIO (cin.tie(0), cout.tie(0), ios::sync_with_stdio(false)) #define precise(i) fixed << setprecision(i) #define rep(i, n) for (int i = 0; i < (int)(n); i++) using namespace std; int main() { fastIO; long long n; cin >> n; cout << (n / 2) * (n / 2) << '\n'; return 0; }