#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <queue>
#include <string>
#include <map>
#include <set>
#include <stack>
#include <tuple>
#include <deque>
#include <array>
#include <numeric>
#include <bitset>
#include <iomanip>
#include <cassert>
#include <chrono>
#include <random>
#include <limits>
#include <iterator>
#include <functional>
#include <sstream>
#include <fstream>
#include <complex>
#include <cstring>
#include <unordered_map>
using namespace std;

using ll = long long;
using P = pair<int, int>;
constexpr int INF = 1001001001;
// constexpr int mod = 1000000007;
constexpr int mod = 998244353;

template<class T>
inline bool chmax(T& x, T y){
    if(x < y){
        x = y;
        return true;
    }
    return false;
}
template<class T>
inline bool chmin(T& x, T y){
    if(x > y){
        x = y;
        return true;
    }
    return false;
}

// https://oeis.org/A110611
// a(n) = (n^3+3*n^2+5*n-6)/6 if n is even; a(n)=(n^3+3*n^2+5*n-3)/6 if n is odd.

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

    ll n, ans;
    cin >> n;
    if(n == 1)  ans = 0;
    else if(n % 2 == 0){
        ans = (n * n * n + 3LL * n * n + 5LL * n - 6LL) / 6LL;
    }
    else{
        ans = (n * n * n + 3LL * n * n + 5LL * n - 3LL) / 6LL;
    }
    cout << ans << endl;

    return 0;
}