#include <cstdio>
#include <iostream>
#include <string>
#include <sstream>
#include <stack>
#include <algorithm>
#include <cmath>
#include <queue>
#include <map>
#include <set>
#include <cstdlib>
#include <bitset>
#include <tuple>
#include <assert.h>
#include <deque>
#include <bitset>
#include <iomanip>
#include <limits>
#include <chrono>
#include <random>
#include <array>
#include <unordered_map>
#include <functional>
#include <complex>

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

const long long MAX = 5100000;
const long long INF = 1LL << 60;
const long long mod = 1000000007LL;
//const long long mod = 998244353LL;

using namespace std;
typedef unsigned long long ull;
typedef long long ll;

int main()
{
	/*
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	*/

	ll N; scanf("%lld", &N);
	vector<ll> y(N); for (ll i = 0; i < N; i++) scanf("%lld", &y[i]);
	sort(y.begin(), y.end());
	vector<ll> dp(N + 1, INF);
	if (N == 2) {
		cout << y[1] - y[0] << endl;
		return 0;
	}
	if (N == 3) {
		cout << y[2] - y[0] << endl;
		return 0;
	}
	dp[2] = y[1] - y[0];
	dp[3] = y[2] - y[0];
	for (ll i = 4; i <= N; i++) {
		chmin(dp[i], dp[i - 2] + y[i - 1] - y[i - 2]);
		chmin(dp[i], dp[i - 3] + y[i - 1] - y[i - 3]);
	}
	cout << dp[N] << endl;
	return 0;
}