#include <bits/stdc++.h>
using namespace std;
#define int ll
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pi;
typedef pair<ll, ll> pl;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<double> vd;
typedef vector<bool> vb;
typedef vector<char> vc;
typedef vector<string> vs;
typedef vector<pi> vp;
typedef vector<pl> vpl;
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
cerr.tie(nullptr);
int n, s = 0;
cin >> n;
vi a(n);
for (auto& i : a){
cin >> i;
s += i;
}
sort(a.rbegin(), a.rend());
for (int i = 2; i < n; i += 3){
s -= a[i];
}
cout << s << '\n';
}
