#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <cmath>
using namespace std;
using ll = long long;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    int n;
    cin >> n;

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

    vector<ll> dp(n + 1);
    dp[0] = 0;
    dp[1] = 1LL << 60;
    dp[2] = y[1] - y[0];
    for (int i = 3; i <= n; i++) {
        dp[i] = min(dp[i - 2] + (y[i - 1] - y[i - 2]), dp[i - 3] + (y[i - 1] - y[i - 3]));
    }

    cout << dp[n] << endl;

    return 0;
}