#include <bits/stdc++.h>
using namespace std;

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

    int n;
    cin >> n;
    vector<int> ys(n);
    for (int i = 0; i < n; i++) cin >> ys[i];
    sort(ys.begin(), ys.end());
    if (n == 2) {
        cout << ys[1] - ys[0] << endl;
        return 0;
    }
    if (n == 3) {
        cout << ys[2] - ys[0] << endl;
        return 0;
    }
    vector<vector<long long>> dp(n, vector<long long>(2, 1e9));
    dp[1][0] = ys[1] - ys[0];
    dp[2][1] = ys[2] - ys[0];
    for (int i = 3; i < n; i++) {
        dp[i][0] = min(dp[i - 2][0], dp[i - 2][1]) + ys[i] - ys[i - 1];
        dp[i][1] = min(dp[i - 3][0], dp[i - 3][1]) + ys[i] - ys[i - 2];
    }
    cout << min(dp[n - 1][0], dp[n - 1][1]) << endl;
}