#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
#include <set>
#include <map>
#define INF 1e9
typedef long long ll;
using namespace std;
void solve()
{
int n; cin >> n;
vector<int>v(n);
int ans = 0;
for (int i = 0; i < n; i++) {
cin >> v[i];
ans += v[i];
}
sort(v.rbegin(), v.rend());
for (int i = 0; i < n; i++) {
if ((i + 1) % 3 == 0)ans -= v[i];
}
cout << ans << "\n";
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
int t = 1;// cin >> t;
while (t--) solve();
return 0;
}
