#include <cstdio>
#include <iostream>
#include <algorithm>
#include <vector>
#include <map>
#include <functional>

using namespace std;
typedef long long int ll;

#define repi(i,a,b) for(ll i=a;i<b;i++)
#define rep(i,a) repi(i,0,a)
#define rrep(i,a) for(ll i=a-1;i>=0;i--)

int main(){
  ll N;
  cin >> N;
  ll Y[N];
  rep(i, N) cin >> Y[i];
  sort(Y, Y+N);

  vector<ll> dp(1, 0);
  dp.push_back(10e10);
  dp.push_back(Y[1] - Y[0]);
  repi(i, 2, N){
    ll tmp3 = dp[i-2] + (Y[i] - Y[i-2]);
    ll tmp2 = dp[i-1] + (Y[i] - Y[i-1]);
    dp.push_back(tmp3 < tmp2 ? tmp3 : tmp2);
  }
  cout << dp[N] << endl;
  return 0;
}