using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var n = NN;
        var y = NList;
        Array.Sort(y);
        WriteLine(Star(n, y));
    }
    static long Star(int n, int[] y)
    {
        var list = new List<Points>();
        for (var i = 0; i < n; ++i)
        {
            if (i == 0 || y[i] != y[i - 1]) list.Add(new Points(y[i], 1));
            else ++list[^1].Count;
        }
        var INF = long.MaxValue / 2;
        var dp = Enumerable.Repeat(INF, list.Count + 1).ToArray();
        dp[0] = 0;
        for (var i = 0; i < list.Count; ++i)
        {
            if (list[i].Count > 1) dp[i + 1] = Math.Min(dp[i + 1], dp[i]);
            if (i > 0) dp[i + 1] = Math.Min(dp[i + 1], dp[i - 1] + list[i].Y - list[i - 1].Y);
            if (i > 1) dp[i + 1] = Math.Min(dp[i + 1], dp[i - 2] + list[i].Y - list[i - 2].Y);
        }
        return dp[^1];
    }
    class Points
    {
        public int Y;
        public int Count;
        public Points(int y, int count)
        {
            Y = y; Count = count;
        }
    }
}