#define _CRT_SECURE_NO_WARNINGS
#include<iostream>
#include<sstream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<climits>
#include<cmath>
#include<string>
#include<vector>
#include<set>
#include<map>
#include<queue>
#include<numeric>
#include<functional>
#include<algorithm>
#include<bitset>
#include<tuple>
#include<unordered_set>
#include<unordered_map>
#include<random>
#include<array>
#include<cassert>
using namespace std;
#define INF (1<<29)
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define all(v) v.begin(),v.end()
#define uniq(v) v.erase(unique(all(v)),v.end())



int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);

	int n;
	cin >> n;
	vector<long long> y(n);
	rep(i, n)cin >> y[i];
	sort(all(y));

	vector<long long> dp(n + 1, 1LL << 60);
	dp[0] = 0;
	rep(i,n) {
		if (i + 1 < n) {
			dp[i + 2] = min(dp[i + 2], dp[i] + y[i + 1] - y[i]);
		}
		if (i + 2 < n) {
			dp[i + 3] = min(dp[i + 3], dp[i] + y[i + 2] - y[i]);
		}
	}

	cout << dp[n] << endl;




	return 0;
}