// sum for k=1..n of {k*(k+1) if it does not divide by 4}
#include <iostream>
#include <numeric>
#include <ranges>
using namespace std;

int main () {
    int n;
    cin >> n;
    auto ans = ranges::iota_view (1) | views::take (n) |
               views::transform ([] (int x) {return x * (x + 1);}) |
               views::filter ([] (int x) {return x % 4 != 0;}) |
               views::common;
    auto s = accumulate (ans.begin (), ans.end (), 0LL);
    cout << s << endl;
    return 0;
}