const INF: isize = 1isize << 60;

fn main() {
    let mut n = String::new();
    std::io::stdin().read_line(&mut n).ok();
    let n: usize = n.trim().parse().unwrap();
    let mut y = String::new();
    std::io::stdin().read_line(&mut y).ok();
    let mut y: Vec<isize> = y.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();

    y.sort();
    if n <= 3 {
        println!("{}", y[n-1]-y[0]);
        return;
    }
    let mut dp = vec![INF; n-3];
    dp[0] = y[n-1]-y[n-2]+y[1]-y[0];
    for i in 0..n-4 {
        dp[i+1] = dp[i+1].min(dp[i] + y[i+2] - y[i+1]);
        let idx = (i+2).min(n-4);
        dp[idx] = dp[idx].min(dp[i] + y[i+3] - y[i+2]);
    }
    println!("{}", dp[n-4]);
}