/* ldmm is n00b */
#include <bits/stdc++.h>
using namespace std;
#define Cerr cerr << "\nTest: "
#define endl "\n"
#define fi first
#define se second
#define pb push_back
#ifdef RICARDO
#define bug(x) cerr << #x << " = " << (x) << endl;
#define block if(1)
#else
#define bug(x) "IDINGO"
#define block if(0)
#endif
template<class T> bool mini(T &a, T b) { return a > b ? (a = b, true) : false; }
template<class T> bool maxi(T &a, T b) { return a < b ? (a = b, true) : false; }
typedef pair<int, int> pii;
typedef long long ll;
typedef double ld;
const int N=1e5+10;
int a[N];
int n;
signed main()
{
ios::sync_with_stdio(false);
cin.tie(nullptr);
cout.precision(10);
cout << fixed;
#ifdef LOCAL
freopen("i", "r", stdin);
freopen("o", "w", stdout);
#endif
cin>>n;
for(int i=0;i<n;++i)cin>>a[i];
sort(a,a+n,greater<int>());
ll ans=0;
for(int i=0;i<n;++i){
if(i%3==2)continue;
ans+=a[i];
}
cout<<ans;
#ifdef LOCAL
cerr << "\nTime elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << " s.\n";
#endif
}
