#include <iostream>
#include <fstream>
#include <deque>
#include <algorithm>
using namespace std;

int a[100000];
deque<int> ans;
int main() {
    ifstream in("maxsum.in");
    cin.rdbuf(in.rdbuf());
    ofstream out("maxsum.out");
    cout.rdbuf(out.rdbuf());
    int N;
    cin >> N;
    for (long long i = 0; i < N; ++i) {
        cin >> a[i];
    }
    sort(a+0, a+N);
    for (long long i = N-1; i>=0; --i) {
        if (ans.empty()) {
            ans.push_back(a[i]);
        }else{
        if (ans.front()>ans.back()) {
            ans.push_front(a[i]);
        }else{
            ans.push_back(a[i]);
        }
        }
    }
    long long sum = 0;
    for (long long i = 0; i < N-1; ++i) {
        sum += ans[i]*ans[i+1];
        //cout << ans[i] << " ";
    }
    sum += ans[0]*ans[N-1];
    cout << sum;
    return 0;
}