#include <bits/stdc++.h>
using namespace std;
using ll = long long;

signed main() {
    ll N;
    cin >> N;
    if (N == 1) {
        cout << 0 << endl;
        return 0;
    }
    ll num = 1;
    vector<ll> A, B;
    for (ll i = 0; i < N; i++) {
        if (i % 2 == 0) {
            if (i % 4 == 0) {
                A.push_back(num);
            } else {
                B.push_back(num);
            }
            num = N - num + 1;
        } else {
            if (i % 4 == 1) {
                B.push_back(num);
            } else {
                A.push_back(num);
            }
            num = N - num + 2;
        }
    }
    reverse(B.begin(), B.end());
    A.insert(A.end(), B.begin(), B.end());
    ll res = 0;
    for (ll i = 0; i < N; i++) {
        res += A[i] * A[(i + 1) % N];
    }
    cout << res << endl;
}