#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <iostream>
#include <cctype>
#include <ctime>
#include <set>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <utility>
#include <string>
#include <map>
#define ll long long
using namespace std;
const int M = 1000000007;
int n, c, s, x;
vector <int> v;
int main() {
//freopen("input.txt", "r", stdin);
//freopen("output.txt", "w", stdout);
cin >> n;
for (int i = 0; i < n; i++){
cin >> x; s += x;
v.push_back(x);
}
c = n-3;
sort(v.begin(), v.end());
for (int i = c; i >= 0; i -= 3){
s -= v[i];
}
cout << s;
return 0;
}
