fn main() {
    input! {
        n: usize,
        k: usize,
        a: [i64; n],
    }
    let geta = a.iter().map(|a| std::cmp::max(0, *a)).sum::<i64>();
    if k == 1 {
        println!("{}", geta);
        return;
    }
    let mut a = a.iter().map(|a| a.abs()).collect::<Vec<_>>();
    a.sort();
    let mut h = std::collections::BinaryHeap::new();
    h.push((-a[0], 0, 1));
    for _ in 2..k {
        let (s, x, bit) = h.pop().unwrap();
        if x + 1 < n {
            h.push((s + a[x] - a[x + 1], x + 1, bit ^ (3 << x)));
        }
        if x > 0 && bit >> (x - 1) & 1 == 0 {
            h.push((s - a[x - 1], x, bit | (1 << (x - 1))));
        }
    }
    println!("{}", geta + h.pop().unwrap().0);
}

// ---------- begin input macro ----------
// reference: https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
#[macro_export]
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
    ($($r:tt)*) => {
        let s = {
            use std::io::Read;
            let mut s = String::new();
            std::io::stdin().read_to_string(&mut s).unwrap();
            s
        };
        let mut iter = s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}

#[macro_export]
macro_rules! input_inner {
    ($iter:expr) => {};
    ($iter:expr, ) => {};
    ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
}

#[macro_export]
macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };
    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };
    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };
    ($iter:expr, bytes) => {
        read_value!($iter, String).bytes().collect::<Vec<u8>>()
    };
    ($iter:expr, usize1) => {
        read_value!($iter, usize) - 1
    };
    ($iter:expr, $t:ty) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}
// ---------- end input macro ----------