#include<iostream>
#include<string>
#include<iomanip>
#include<cmath>
#include<vector>
#include<algorithm>

using namespace std;

#define int long long
#define endl "\n"

constexpr long long INF = (long long)1e18;
constexpr long long MOD = 1'000'000'007; 

string yn(bool f){return f?"Yes":"No";}
string YN(bool f){return f?"YES":"NO";}


int N;
vector<int> a, sum;

bool check(int m, int x){
	int y = x / 2;
	
	if(m == 0) return true;
	
	if(x%2) {
		if(m > min(y, N - y - 3)) {
			return false;
		} else {
			int a = sum[y] - sum[y - m];
			int b = sum[N] - sum[N - m];
			
			if(a <= b) return true;
			else return false;
		}
	} else {
		if(m > min(y, N - y - 2)) {
			return false;
		} else {
			int a = sum[y] - sum[y - m];
			int b = sum[N] - sum[N - m];
			
			if(a <= b) return true;
			else return false;
		}
	}
}

signed main(){
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	cout<<fixed<<setprecision(10);
	
	int ans = 0;
	
	cin>>N;
	
	a.resize(N);
	sum.resize(N+1);
	
	for(int i = 0; i < N; i++){
		cin>>a[i];
		a[i] <<= 1;
	}
	
	sort(a.begin(), a.end());
	
	for(int i = 0; i < N; i++){
		sum[i+1] = a[i] + sum[i];
	}
	
	for(int i = 0; i < N * 2; i += 2){
		int l = 0, h = N * 2, m = 0;
		
		while(l + 1 < h){
			m = (l + h) >> 1;
			
			if(check(m, i)){
				l = m;
			} else {
				h = m;
			}
		}
			
		int temp = 0;
		
		int A = sum[i/2] - sum[i/2 - l];
		int B = sum[N] - sum[N - l];
		
		temp = A + B - l * (a[i/2] + a[(i + 1)/2]);
		
		ans = max(ans, temp);
		
	}
	
	cout<<ans/2<<endl;
	
	return 0;
}