/* -*- coding: utf-8 -*-
 *
 * 838.cc:  No.838 Noelちゃんと星々3 - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 100000;
const long long LINF = 1LL << 62;

/* typedef */

typedef long long ll;

/* global variables */

int ys[MAX_N];
ll dp[MAX_N + 1];

/* subroutines */

inline void setmin(ll &a, ll b) { if (a > b) a = b; }

/* main */

int main() {
  int n;
  scanf("%d", &n);

  for (int i = 0; i < n; i++) scanf("%d", ys + i);
  sort(ys, ys + n);

  fill(dp, dp + n + 1, LINF);
  dp[0] = 0;

  for (int i = 0; i < n; i++)
    if (dp[i] < LINF) {
      if (i + 1 < n) setmin(dp[i + 2], dp[i] + ys[i + 1] - ys[i]);
      if (i + 2 < n) setmin(dp[i + 3], dp[i] + ys[i + 2] - ys[i]);
    }

  printf("%lld\n", dp[n]);
  //for (int i = 0; i <= n; i++) printf("%lld ", dp[i]); putchar('\n');
  return 0;
}