#include <bits/stdc++.h>

using namespace std;

long long sumOfGroup(long k) {
    // Return the sum of the elements of the k'th group.
    long long sum = 0;
    long long q = k * k;
    if (k % 2 != 0) {
        sum += q;
        for (int i = 0; i < k/2; i++) {
            sum += q + (i + i + 2);
            sum += q - (i + i + 2);
        }
    } else {
        for (int i = 0; i < k/2; i++) {
                sum += q + (i + i + 1);
                sum += q - (i + i + 1);
            }
    }
    if (sum < 0) return LONG_MAX;
    else return sum;
}

int main() {
    long k;
    cin >> k;
    long long answer = sumOfGroup(k);
    cout << answer << endl;
    return 0;
}