#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
//
//#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("-O3")
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("fast-math")
//#pragma GCC optimize("no-stack-protector")
#define F first
#define S second
#define sz(x) int(x.size())
#define pb push_back
#define pf push_front
#define N 100010
#define M ll(1e9 + 7)
#define inf 1e9 + 1e9
using namespace std;
//using namespace __gnu_pbds;
typedef long double ld;
typedef long long ll;
typedef unsigned long long ull;
typedef short int si;
typedef array <int, 3> a3;
typedef array <int, 4> a4;
typedef pair <int, int> pt;
//typedef tree <int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
int main()
{
//freopen("mining.in", "r", stdin); freopen("mining.out", "w", stdout);
ios_base::sync_with_stdio(0); istream::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int n;
cin >> n;
int a[n];
for (int i = 0; i < n; i++) cin >> a[i];
sort(a, a + n);
reverse(a, a + n);
ll sum = 0;
for (int i = 0; i < n; i++)
{
if ((i + 1) % 3 == 0) continue;
sum += a[i];
}
cout << sum << endl;
}
