// Created by AboAbdoMC
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#define db1(x) cout<<#x<<"="<<x<<'\n'
#define db2(x,y) cout<<#x<<"="<<x<<","<<#y<<"="<<y<<'\n'
#define db3(x,y,z) cout<<#x<<"="<<x<<","<<#y<<"="<<y<<","<<#z<<"="<<z<<'\n'
#define rep(i,n) for(int i=0;i<(n);++i)
#define repA(i,a,n) for(int i=a;i<=(n);++i)
#define repD(i,a,n) for(int i=a;i>=(n);--i)
#define f first
#define s second
#define pb push_back
#define mp make_pair
#define ll long long
using namespace std;
using namespace __gnu_pbds;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> indexed_set;
const int OO = 1e9+7;
const int MOD = 1e9+7;
const int N = 1e5+7;
int c[N];
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n;
cin >> n;
rep(i,n) cin >> c[i];
sort(c,c+n,greater<int>());
ll sum = 0;
rep(i,n)
{
if (i%3 != 2) sum += c[i];
}
cout << sum << '\n';
return 0;
}
