include<iostream>

include <algorithm>

define SIZE 100

using namespace std;

int main()
{
int A[SIZE], n;
cin >> n;
for (int i = 0; i < n; i++)
cin >> A[i];
sort(A, A + n, greater<int>());
long long total = 0;
for (int i = 0; i < n; i++) {
if (i % 3 != 2) {
total += A[i];
}
}
cout << total;
return 0;
}