#define _USE_MATH_DEFINES
#include <cstdio>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <complex>
#include <string>
#include <vector>
#include <array>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <limits>
#include <climits>
#include <cfloat>
#include <functional>
#include <iterator>
#include <memory>
#include <regex>
using namespace std;

const long long INF = LLONG_MAX / 2;

int main()
{
    int n;
    cin >> n;
    vector<long long> v(n);
    for(int i=0; i<n; ++i)
        cin >> v[i];
    sort(v.begin(), v.end());

    vector<long long> dp(n+1, INF);
    dp[0] = 0;
    for(int i=0; i<n-1; ++i){
        long long tmp = v[i+1] - v[i];
        dp[i+2] = min(dp[i+2], dp[i] + tmp);
        if(i < n - 2){
            tmp += v[i+2] - v[i+1];
            dp[i+3] = min(dp[i+3], dp[i] + tmp);
        }
    }
    cout << dp[n] << endl;

    return 0;
}