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

int main () {
    int n;
    cin >> n;                               // 7
    vector <int> v (n);
    iota (v.begin (), v.end (), 1);         // 1 2 3 4 5 6 7
    transform (v.begin (), v.end (), v.begin (),
        [&] (int x) {return x * (x + 1);}); // 2 6 12 20 30 42 56
    auto new_end = remove_if (v.begin (), v.end (),
        [&] (int x) {return x % 4 == 0;});  // 2 6 30 42|30 42 56
    auto s = accumulate (v.begin (), new_end, 0LL);
    cout << s << endl;                      // 80
    return 0;
}