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

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int[] heights = new int[n];
        for (int i = 0; i < n; i++) {
            heights[i] = sc.nextInt();
        }
        Arrays.sort(heights);
        long[][] dp = new long[n][3];
        dp[0][1] = Long.MAX_VALUE / 2;
        dp[0][2] = Long.MAX_VALUE / 2;
        dp[1][0] = Long.MAX_VALUE / 2;
        dp[1][1] = heights[1] - heights[0];
        dp[1][2] = Long.MAX_VALUE / 2;
        for (int i = 2; i < n; i++) {
            dp[i][0] = Math.min(dp[i - 1][1], dp[i - 1][2]);
            dp[i][1] = dp[i - 1][0] + heights[i] - heights[i - 1];
            dp[i][2] = dp[i - 1][1] + heights[i] - heights[i - 1];
        }
        System.out.println(Math.min(dp[n - 1][1], dp[n - 1][2]));
    }
}

class Utilities {
    static String arrayToLineString(Object[] arr) {
        return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n"));
    }
    
    static String arrayToLineString(int[] arr) {
        return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new));
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public int[] nextIntArray() throws Exception {
        return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}