#include <bits/stdc++.h>
#ifdef _DEBUG
#include "debug.hpp"
#else
#define debug(...)
#endif
#define REP(i, m, n) for(int i = (int)(m); i < (int)(n); ++i)
#define rep(i, n) REP(i, 0, n)
using namespace std;
using ll = long long; using ld = long double; using pll = pair<ll, ll>;
const int INF = 1<<30; const ll LINF = 1LL<<60; const ld PI = 3.1415926535897932;
template<class T, class U> inline bool chmax(T &a, const U &b) { if(a < b) { a = b; return true; } return false; }
template<class T, class U> inline bool chmin(T &a, const U &b) { if(a > b) { a = b; return true; } return false; }

ll dp[101000];

signed main() {
  cin.tie(0); ios::sync_with_stdio(false);
  int n;
  cin >> n;
  vector<ll> y(n);
  rep(i, n) cin >> y[i];
  sort(y.begin(), y.end());
  rep(i, 101000) dp[i] = LINF;
  dp[0] = 0;
  rep(i, n) {
    if(i+1 < n) chmin(dp[i+2], dp[i]+y[i+1]-y[i]);
    if(i+2 < n) chmin(dp[i+3], dp[i]+y[i+2]-y[i]);
  }
  cout << dp[n] << '\n';
  return 0;
}