use std::io::*;

fn main() {
    let mut s: String = String::new();
    std::io::stdin().read_to_string(&mut s).ok();
    let mut itr = s.trim().split_whitespace();
    let n: usize = itr.next().unwrap().parse().unwrap();
    let k: usize = itr.next().unwrap().parse().unwrap();
    let a: Vec<i64> = (0..n)
        .map(|_| itr.next().unwrap().parse().unwrap())
        .collect();

    let mut b = Vec::new();
    let mut c = Vec::new();
    for i in 0..n {
        b.push((a[0] - a[i]).abs());
        c.push((a[n - 1] - a[i]).abs());
    }
    b.sort();
    c.sort();
    let mut ans1 = 0;
    let mut ans2 = 0;
    for i in 0..k {
        ans1 += b[i];
        ans2 += c[i];
    }
    for i in k..n {
        ans1 -= b[i];
        ans2 -= c[i];
    }
    println!("{}", std::cmp::min(ans1, ans2));
}