#include <iostream>
#include <algorithm>

typedef long long ll;

using namespace std;

ll* a;
ll* cache;
ll n;

ll algo()
{
    if (n == 2) return 0;

    cache[n - 1] = 0;
    cache[n - 2] = a[n - 1] - a[n - 2];

    for (ll i = n - 3; i; i--)
        cache[i] = min((a[i + 1] - a[i]) + cache[i + 1], (a[i + 2] - a[i + 1]) + cache[i + 2]);

    return cache[1];
}

int main()
{
    cin >> n;

    a = new ll[n];
    cache = new ll[n];

    for (ll i = 0; i < n; i++)
    {
        cache[i] = -1;
        cin >> a[i];
    }

    sort(a, a + n);

    /*
    for (ll i = 0; i < n; i++) cout << a[i] << " ";
    cout << endl;*/

    cout << algo() + (a[1] - a[0]) << endl;

    /*
    for (ll i = 0; i < n; i++) cout << cache[i] << " ";
    cout << endl;
    */
}