import java.io.*;
import java.util.*;


public class Main_yukicoder838 {

	private static Scanner sc;
	private static Printer pr;

	private static void solve() {
		final long INF = Long.MAX_VALUE / 2;

		int n = sc.nextInt();

		int[] y = new int[n];
		for (int i = 0; i < n; i++) {
			y[i] = sc.nextInt();
		}
		Arrays.sort(y);

		long[] dp2 = new long[n + 1];
		long[] dp3 = new long[n + 1];
		Arrays.fill(dp2, INF);
		Arrays.fill(dp3, INF);
		dp2[0] = dp3[0] = 0;
		for (int i = 0; i < n; i++) {
			if (i + 1 - 2 >= 0) {
				dp2[i + 1] = Math.min(dp2[i + 1], dp2[i + 1 - 2] + y[i] - y[i - 1]);
				dp2[i + 1] = Math.min(dp2[i + 1], dp3[i + 1 - 2] + y[i] - y[i - 1]);
			}
			if (i + 1 - 3 >= 0) {
				dp3[i + 1] = Math.min(dp3[i + 1], dp3[i + 1 - 3] + y[i] - y[i - 1] + y[i - 1] - y[i - 2]);
				dp3[i + 1] = Math.min(dp3[i + 1], dp2[i + 1 - 3] + y[i] - y[i - 1] + y[i - 1] - y[i - 2]);
			}
		}
		
		pr.println(Math.min(dp2[n], dp3[n]));
	}
	
	// ---------------------------------------------------
	public static void main(String[] args) {
		sc = new Scanner(System.in);
		pr = new Printer(System.out);
			
		solve();
			
		pr.close();
		sc.close();
	}

	static class Printer extends PrintWriter {
		Printer(OutputStream out) {
			super(out);
		}
	}
}