#include<iostream>
#include<cstdio>
#include<cstring>
#include <cstdlib>  
#include <math.h>
#include <cmath>
#include<cctype>
#include<string>
#include<set>
#include<iomanip>
#include <map>
#include<algorithm>
#include <functional>
#include<vector>
#include<climits>
#include<stack>
#include<queue>
#include<bitset>
#include <deque>
#include <climits>
#include <typeinfo>
#include <utility> 
using namespace std;
using ll = long long;
using R = double;
using Data = pair < ll, vector <ll>>;
template<typename T>using min_priority_queue = priority_queue<T, vector<T>, greater<T>>;
const ll MOD = 1e9 + 7;
const ll inf = 1LL << 60;
struct edge { ll from; ll to; ll cost; };
typedef pair<ll, ll>pll;
#define all(x) (x).begin(),(x).end()
#define rep(i,m,n) for(ll i = m;i < n;++i)
#define pb push_back
#define fore(i,a) for(auto &i:a)
#define rrep(i,m,n) for(ll i = m;i >= n;--i)
#define INF INT_MAX/2

ll dp[101010];

int main() {
	ll N;
	cin >> N;
	vector<ll>Y(N);
	rep(i, 0, N)cin >> Y[i];
	sort(all(Y));

	dp[1] = inf;
	dp[2] = Y[1] - Y[0];
	dp[3] = Y[2] - Y[0];
	if (N >= 4) {
		for (int i = 4; i <= N; i++) {
			dp[i] = min(dp[i - 2] + Y[i - 1] - Y[i - 2], dp[i - 3] + Y[i - 1] - Y[i - 3]);
		}
	}
	cout << dp[N] << endl;


	return 0;
}