#include <bits/stdc++.h>
#define int long long
using namespace std;
const long long N = 2e5 + 5;
int a[N];
void solve()
{
int n;
cin >> n;
int sum = 0;
for (int i = 0; i < n; i++)
{
cin >> a[i];
sum += a[i];
}
sort(a, a + n, [&](int a, int b)
{ return a > b; });
for (int i = 2; i < n; i += 3)
{
sum -= a[i];
}
cout << sum;
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(NULL);
cout.tie(NULL);
int t = 1;
// cin >> t;
for (int i = 1; i <= t; i++)
{
// cout << "Case #" << i << ':' << ' ';
solve();
cout << endl;
}
return 0;
}
