#define  _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <algorithm>
#include <utility>
#include <functional>
#include <cstring>
#include <queue>
#include <stack>
#include <math.h>
#include <iterator>
#include <vector>
#include <string>
#include <set>
#include <math.h>
#include <iostream>
#include <random>
#include<map>
#include <iomanip>
#include <time.h>
#include <stdlib.h>
#include <list>
#include <typeinfo>
#include <list>
#include <set>
#include <cassert>
#include<fstream>
#include <unordered_map>
#include <cstdlib>
#include <complex>
using namespace std;
#define Ma_PI 3.141592653589793
#define eps 0.00000001
#define LONG_INF 30000000000000LL
#define GOLD 1.61803398874989484820458
const long long MAX_MOD = 1e6 + 3;
#define REP(i,n) for(long long i = 0;i < n;++i)    
#define seg_size 524288
long long powering(long long now,long long now_go){
	long long ans = 1;
	while (now_go != 0) {
		if (now_go % 2 == 1) {
			ans *= now;
			ans %= MAX_MOD;
		}
		now *= now;
		now %= MAX_MOD;
		now_go /= 2;
	}
	return ans;
}
long long inv(long long now) {
	return powering(now, MAX_MOD - 2LL);
}
long long ans[200000];
int main() {
#define int long long
	long long n;
	cin >> n;
	vector<int> input;
	REP(i, n) {
		int a;
		cin >> a;
		input.push_back(a);
	}
	sort(input.begin(), input.end());
	for (int i = 0; i <= input.size(); ++i) {
		ans[i] = LONG_INF;
	}
	ans[0] = 0;
	for (int i = 0; i < input.size() - 1; ++i) {
		if (i + 2 < input.size()) {
			ans[i + 3] = min(ans[i + 3], ans[i] + input[i + 2] - input[i]);
		}
		if (i + 1 < input.size()) {
			ans[i + 2] = min(ans[i + 2], ans[i] + input[i + 1] - input[i]);
		}
	}
	cout << ans[n] << endl;
	return 0;
}