use std::{cmp::Reverse, collections::BinaryHeap, usize::MAX};

#[allow(unused_imports)]
#[cfg(feature = "dbg")]
use dbg::lg;

fn main() {
    let mut buf = ngtio::with_stdin();
    let n = buf.usize();
    let k = buf.usize();
    let a = buf.vec::<usize>(n);
    let mut queue = Queue::default();
    for &x in &a[..k] {
        queue.insert(x);
    }
    let mut ans = MAX;
    for (i, j) in (0..).zip(k..) {
        let med = queue.left.peek().unwrap();
        let cost =
            (med * queue.left_count - queue.left_sum) + (queue.right_sum - med * queue.right_count);
        ans = ans.min(cost);
        if j == n {
            break;
        }
        queue.remove(a[i]);
        queue.insert(a[j]);
    }
    println!("{}", ans);
}

#[derive(Clone, Debug, Default)]
struct Queue {
    left: BinaryHeap<usize>,
    right: BinaryHeap<Reverse<usize>>,
    left_removed: BinaryHeap<usize>,
    right_removed: BinaryHeap<Reverse<usize>>,
    left_count: usize,
    right_count: usize,
    left_sum: usize,
    right_sum: usize,
}
impl Queue {
    fn insert(&mut self, x: usize) {
        if self.left_count > self.right_count {
            self.move_right();
        }
        self.left.push(x);
        self.left_count += 1;
        self.left_sum += x;
        self.settle();
        if self.is_reversed() {
            self.move_right();
            self.move_left();
        }
    }
    fn remove(&mut self, x: usize) {
        if self.left.peek().map_or(false, |&lmax| x <= lmax) {
            self.left_removed.push(x);
            self.left_count -= 1;
            self.left_sum -= x;
            self.settle();
            if self.left_count < self.right_count {
                self.move_left();
            }
        } else {
            self.right_removed.push(Reverse(x));
            self.right_count -= 1;
            self.right_sum -= x;
            if self.left_count > self.right_count + 1 {
                self.move_right();
            }
        }
    }
    fn is_reversed(&self) -> bool {
        !self.left.is_empty()
            && !self.right.is_empty()
            && self.left.peek().unwrap() > &self.right.peek().unwrap().0
    }
    fn move_left(&mut self) {
        let x = self.right.pop().unwrap().0;
        self.right_sum -= x;
        self.right_count -= 1;
        self.left_sum += x;
        self.left_count += 1;
        self.left.push(x);
        self.settle();
    }
    fn move_right(&mut self) {
        let x = self.left.pop().unwrap();
        self.left_count -= 1;
        self.left_sum -= x;
        self.right_count += 1;
        self.right_sum += x;
        self.right.push(Reverse(x));
        self.settle();
    }
    fn settle(&mut self) {
        while !self.left.is_empty() && self.left.peek() == self.left_removed.peek() {
            self.left.pop().unwrap();
            self.left_removed.pop().unwrap();
        }
        while !self.right.is_empty() && self.right.peek() == self.right_removed.peek() {
            self.right.pop().unwrap();
            self.right_removed.pop().unwrap();
        }
    }
}

// wavelet_matrix {{{
#[allow(dead_code)]
mod wavelet_matrix {
    #![allow(clippy::len_zero)]
    use std::{
        fmt::Debug,
        iter::FromIterator,
        mem::size_of,
        ops::{Bound, Range, RangeBounds},
    };
    const UNIT: usize = size_of::<usize>();
    #[derive(Clone, Default, Hash, PartialEq)]
    pub struct WaveletMatrix {
        table: Vec<StaticBitVec>,
    }
    impl Debug for WaveletMatrix {
        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
            f.debug_list()
                .entries((0..self.len()).map(|i| self.access(i)))
                .finish()
        }
    }
    impl FromIterator<usize> for WaveletMatrix {
        fn from_iter<I: IntoIterator<Item = usize>>(iter: I) -> Self {
            let mut slice = iter.into_iter().map(Into::into).collect::<Vec<_>>();
            Self::from_slice_of_usize_mut(&mut slice)
        }
    }
    impl WaveletMatrix {
        pub fn is_empty(&self) -> bool {
            self.table.is_empty()
        }
        pub fn len(&self) -> usize {
            self.table.first().map_or(0, |row| row.len())
        }
        pub fn lim(&self) -> usize {
            1 << self.table.len()
        }
        pub fn from_slice_of_usize_mut(slice: &mut [usize]) -> Self {
            let ht = slice.iter().copied().max().map_or(0, |value| {
                (value + 1).next_power_of_two().trailing_zeros() as usize
            });
            let table = (0..ht)
                .rev()
                .map(|p| {
                    let res = slice.iter().map(|&value| value >> p & 1 == 1).collect();
                    stable_partition_by_key(slice, |value| value >> p & 1 == 1);
                    res
                })
                .collect();
            Self { table }
        }
        pub fn access(&self, mut i: usize) -> usize {
            assert!(i < self.table[0].len());
            let mut ans = 0;
            for row in &self.table {
                let here = row.access(i);
                i = next_position(row, i, row.access(i));
                ans <<= 1;
                ans |= here as usize;
            }
            ans
        }
        pub fn range_freq(
            &self,
            index_range: impl RangeBounds<usize>,
            value_range: impl RangeBounds<usize>,
        ) -> usize {
            self.span(open(index_range, self.len()))
                .range_freq(&open(value_range, self.lim()))
        }
        pub fn next_value(
            &self,
            index_range: impl RangeBounds<usize>,
            value_range: impl RangeBounds<usize>,
        ) -> Option<usize> {
            self.span(open(index_range, self.len()))
                .next_value(&open(value_range, self.lim()))
        }
        pub fn prev_value(
            &self,
            index_range: impl RangeBounds<usize>,
            value_range: impl RangeBounds<usize>,
        ) -> Option<usize> {
            self.span(open(index_range, self.len()))
                .prev_value(&open(value_range, self.lim()))
        }
        pub fn quantile(
            &self,
            k: usize,
            index_range: impl RangeBounds<usize>,
            value_range: impl RangeBounds<usize>,
        ) -> Option<usize> {
            self.span(open(index_range, self.len()))
                .quantile(k, &open(value_range, self.lim()))
                .ok()
        }
        fn span(&self, index_range: Range<usize>) -> Span<'_> {
            Span {
                span: &self.table,
                index_range,
                value_range: 0..self.lim(),
            }
        }
    }
    fn stable_partition_by_key(slice: &mut [usize], is_upper: impl Fn(usize) -> bool) -> usize {
        let mut upper = Vec::new();
        let mut i = 0;
        for j in 0..slice.len() {
            if is_upper(slice[j]) {
                upper.push(slice[j]);
            } else {
                slice[i] = slice[j];
                i += 1;
            }
        }
        slice[i..].copy_from_slice(&upper);
        i
    }
    fn next_position(row: &StaticBitVec, i: usize, which: bool) -> usize {
        match which {
            false => i - row.rank(i),
            true => row.len() - row.rank(row.len()) + row.rank(i),
        }
    }
    fn next_position_range(row: &StaticBitVec, range: &Range<usize>, which: bool) -> Range<usize> {
        next_position(row, range.start, which)..next_position(row, range.end, which)
    }
    #[derive(Clone, Debug, Default, Hash, PartialEq)]
    pub struct StaticBitVec {
        len: usize,
        rank: Vec<usize>,
        pattern: Vec<usize>,
    }
    impl FromIterator<bool> for StaticBitVec {
        fn from_iter<T: IntoIterator<Item = bool>>(iter: T) -> Self {
            let mut iter = iter.into_iter();
            let mut rank = Vec::new();
            let mut pattern = Vec::new();
            let mut rank_c = 0;
            let mut pattern_c = 0;
            let mut len = 0;
            'OUTER: loop {
                rank.push(rank_c);
                for i in 0..UNIT {
                    match iter.next() {
                        None => {
                            pattern.push(pattern_c);
                            break 'OUTER;
                        }
                        Some(false) => (),
                        Some(true) => {
                            pattern_c |= 1 << i;
                            rank_c += 1;
                        }
                    }
                    len += 1;
                }
                pattern.push(pattern_c);
                pattern_c = 0;
            }
            Self { len, rank, pattern }
        }
    }
    impl StaticBitVec {
        pub fn is_empty(&self) -> bool {
            self.len == 0
        }
        pub fn len(&self) -> usize {
            self.len
        }
        pub fn access(&self, i: usize) -> bool {
            assert!(i < self.len);
            let (q, r) = divrem(i, UNIT);
            self.pattern[q] >> r & 1 == 1
        }
        pub fn rank(&self, end: usize) -> usize {
            assert!(end <= self.len);
            let (q, r) = divrem(end, UNIT);
            self.rank[q] + (self.pattern[q] & ((1 << r) - 1)).count_ones() as usize
        }
        pub fn select(&self, target: usize) -> usize {
            if target == 0 {
                return 0;
            }
            let mut lr = 0..self.rank.len();
            while 1 < lr.len() {
                let c = midpoint(&lr);
                *if self.rank[c] < target {
                    &mut lr.start
                } else {
                    &mut lr.end
                } = c;
            }
            let q = lr.start;
            let mut lr = 0..UNIT;
            while 1 < lr.len() {
                let c = midpoint(&lr);
                *if (self.rank[q] + (self.pattern[q] & ((1 << c) - 1)).count_ones() as usize)
                    < target
                {
                    &mut lr.start
                } else {
                    &mut lr.end
                } = c;
            }
            q * UNIT + lr.end
        }
    }
    #[derive(Clone, Debug, Hash, PartialEq)]
    struct Span<'a> {
        span: &'a [StaticBitVec],
        index_range: Range<usize>,
        value_range: Range<usize>,
    }
    impl<'a> Span<'a> {
        fn left_down(&self) -> Self {
            Self {
                span: &self.span[1..],
                index_range: next_position_range(&self.span[0], &self.index_range, false),
                value_range: self.value_range.start..midpoint(&self.value_range),
            }
        }
        fn right_down(&self) -> Self {
            Self {
                span: &self.span[1..],
                index_range: next_position_range(&self.span[0], &self.index_range, true),
                value_range: midpoint(&self.value_range)..self.value_range.end,
            }
        }
        fn range_freq(&self, target: &Range<usize>) -> usize {
            if is_disjoint_with(&self.value_range, target) || self.index_range.len() == 0 {
                0
            } else if is_subrange_of(&self.value_range, target) {
                self.index_range.len()
            } else {
                self.left_down().range_freq(target) + self.right_down().range_freq(target)
            }
        }
        fn next_value(&self, target: &Range<usize>) -> Option<usize> {
            if is_disjoint_with(&self.value_range, target) || self.index_range.len() == 0 {
                None
            } else if self.value_range.len() == 1 {
                Some(self.value_range.start)
            } else {
                self.left_down()
                    .next_value(target)
                    .or_else(|| self.right_down().next_value(target))
            }
        }
        fn prev_value(&self, target: &Range<usize>) -> Option<usize> {
            if is_disjoint_with(&self.value_range, target) || self.index_range.len() == 0 {
                None
            } else if self.value_range.len() == 1 {
                Some(self.value_range.start)
            } else {
                self.right_down()
                    .prev_value(target)
                    .or_else(|| self.left_down().prev_value(target))
            }
        }
        fn quantile(&self, k: usize, target: &Range<usize>) -> Result<usize, usize> {
            let ans = if is_disjoint_with(&self.value_range, target) {
                Err(0)
            } else if is_subrange_of(&self.value_range, target) && self.index_range.len() <= k {
                Err(self.index_range.len())
            } else if self.value_range.len() == 1 {
                Ok(self.value_range.start)
            } else {
                self.left_down().quantile(k, target).or_else(|len| {
                    self.right_down()
                        .quantile(k - len, target)
                        .map_err(|e| e + len)
                })
            };
            ans
        }
    }
    fn midpoint(range: &Range<usize>) -> usize {
        range.start + (range.end - range.start) / 2
    }
    fn is_disjoint_with(lhs: &Range<usize>, rhs: &Range<usize>) -> bool {
        lhs.end <= rhs.start || rhs.end <= lhs.start
    }
    fn is_subrange_of(lhs: &Range<usize>, rhs: &Range<usize>) -> bool {
        rhs.start <= lhs.start && lhs.end <= rhs.end
    }
    fn divrem(num: usize, den: usize) -> (usize, usize) {
        let q = num / den;
        (q, num - q * den)
    }
    fn open(range: impl RangeBounds<usize>, len: usize) -> Range<usize> {
        (match range.start_bound() {
            Bound::Included(&l) => l,
            Bound::Excluded(&l) => l + 1,
            Bound::Unbounded => 0,
        })..(match range.end_bound() {
            Bound::Included(&r) => r + 1,
            Bound::Excluded(&r) => r,
            Bound::Unbounded => len,
        })
    }
}
// }}}
// template {{{
#[cfg(not(feature = "dbg"))]
#[allow(unused_macros)]
#[macro_export]
macro_rules! lg {
    ($($expr:expr),*) => {};
}
#[allow(dead_code)]
mod ngtio {
    mod i {
        pub use self::{
            multi_token::{Leaf, Parser, ParserTuple, RawTuple, Tuple, VecLen},
            token::{Token, Usize1},
        };
        use std::{
            io::{self, BufRead},
            iter,
        };
        pub fn with_stdin() -> Tokenizer<io::BufReader<io::Stdin>> {
            io::BufReader::new(io::stdin()).tokenizer()
        }
        pub fn with_str(src: &str) -> Tokenizer<&[u8]> {
            src.as_bytes().tokenizer()
        }
        pub struct Tokenizer<S: BufRead> {
            queue: Vec<String>, // FIXME: String のみにすると速そうです。
            scanner: S,
        }
        macro_rules! prim_method {
            ($name:ident: $T:ty) => {
                pub fn $name(&mut self) -> $T {
                    <$T>::leaf().parse(self)
                }
            };
            ($name:ident) => {
                prim_method!($name: $name);
            };
        }
        macro_rules! prim_methods {
            ($name:ident: $T:ty; $($rest:tt)*) => {
                prim_method!($name:$T);
                prim_methods!($($rest)*);
            };
            ($name:ident; $($rest:tt)*) => {
                prim_method!($name);
                prim_methods!($($rest)*);
            };
            () => ()
        }
        impl<S: BufRead> Tokenizer<S> {
            pub fn token(&mut self) -> String {
                self.load();
                self.queue.pop().expect("入力が終了したのですが。")
            }
            pub fn new(scanner: S) -> Self {
                Self {
                    queue: Vec::new(),
                    scanner,
                }
            }
            fn load(&mut self) {
                while self.queue.is_empty() {
                    let mut s = String::new();
                    let length = self.scanner.read_line(&mut s).unwrap(); // 入力が UTF-8 でないときにエラーだそうです。
                    if length == 0 {
                        break;
                    }
                    self.queue = s.split_whitespace().rev().map(str::to_owned).collect();
                }
            }
            pub fn skip_line(&mut self) {
                assert!(
                    self.queue.is_empty(),
                    "行の途中で呼ばないでいただきたいです。現在のトークンキュー: {:?}",
                    &self.queue
                );
                self.load();
            }
            pub fn end(&mut self) {
                self.load();
                assert!(self.queue.is_empty(), "入力はまだあります！");
            }
            pub fn parse<T: Token>(&mut self) -> T::Output {
                T::parse(&self.token())
            }
            pub fn parse_collect<T: Token, B>(&mut self, n: usize) -> B
            where
                B: iter::FromIterator<T::Output>,
            {
                iter::repeat_with(|| self.parse::<T>()).take(n).collect()
            }
            pub fn tuple<T: RawTuple>(&mut self) -> <T::LeafTuple as Parser>::Output {
                T::leaf_tuple().parse(self)
            }
            pub fn vec<T: Token>(&mut self, len: usize) -> Vec<T::Output> {
                T::leaf().vec(len).parse(self)
            }
            pub fn vec_tuple<T: RawTuple>(
                &mut self,
                len: usize,
            ) -> Vec<<T::LeafTuple as Parser>::Output> {
                T::leaf_tuple().vec(len).parse(self)
            }
            pub fn vec2<T: Token>(&mut self, height: usize, width: usize) -> Vec<Vec<T::Output>> {
                T::leaf().vec(width).vec(height).parse(self)
            }
            pub fn vec2_tuple<T>(
                &mut self,
                height: usize,
                width: usize,
            ) -> Vec<Vec<<T::LeafTuple as Parser>::Output>>
            where
                T: RawTuple,
            {
                T::leaf_tuple().vec(width).vec(height).parse(self)
            }
            prim_methods! {
                u8; u16; u32; u64; u128; usize;
                i8; i16; i32; i64; i128; isize;
                f32; f64;
                char; string: String;
            }
        }
        mod token {
            use super::multi_token::Leaf;
            use std::{any, fmt, marker, str};
            pub trait Token: Sized {
                type Output;
                fn parse(s: &str) -> Self::Output;
                fn leaf() -> Leaf<Self> {
                    Leaf(marker::PhantomData)
                }
            }
            impl<T> Token for T
            where
                T: str::FromStr,
                <Self as str::FromStr>::Err: fmt::Debug,
            {
                type Output = Self;
                fn parse(s: &str) -> Self::Output {
                    s.parse().unwrap_or_else(|_| {
                        panic!("Parse error!: ({}: {})", s, any::type_name::<Self>(),)
                    })
                }
            }
            pub struct Usize1 {}
            impl Token for Usize1 {
                type Output = usize;
                fn parse(s: &str) -> Self::Output {
                    usize::parse(s)
                        .checked_sub(1)
                        .expect("Parse error! (Zero substruction error of Usize1)")
                }
            }
        }
        mod multi_token {
            use super::{Token, Tokenizer};
            use std::{io::BufRead, iter, marker};
            pub trait Parser: Sized {
                type Output;
                fn parse<S: BufRead>(&self, server: &mut Tokenizer<S>) -> Self::Output;
                fn vec(self, len: usize) -> VecLen<Self> {
                    VecLen { len, elem: self }
                }
            }
            pub struct Leaf<T>(pub(super) marker::PhantomData<T>);
            impl<T: Token> Parser for Leaf<T> {
                type Output = T::Output;
                fn parse<S: BufRead>(&self, server: &mut Tokenizer<S>) -> T::Output {
                    server.parse::<T>()
                }
            }
            pub struct VecLen<T> {
                pub len: usize,
                pub elem: T,
            }
            impl<T: Parser> Parser for VecLen<T> {
                type Output = Vec<T::Output>;
                fn parse<S: BufRead>(&self, server: &mut Tokenizer<S>) -> Self::Output {
                    iter::repeat_with(|| self.elem.parse(server))
                        .take(self.len)
                        .collect()
                }
            }
            pub trait RawTuple {
                type LeafTuple: Parser;
                fn leaf_tuple() -> Self::LeafTuple;
            }
            pub trait ParserTuple {
                type Tuple: Parser;
                fn tuple(self) -> Self::Tuple;
            }
            pub struct Tuple<T>(pub T);
            macro_rules! impl_tuple {
                ($($t:ident: $T:ident),*) => {
                    impl<$($T),*> Parser for Tuple<($($T,)*)>
                        where
                            $($T: Parser,)*
                            {
                                type Output = ($($T::Output,)*);
#[allow(unused_variables)]
                                fn parse<S: BufRead >(&self, server: &mut Tokenizer<S>) -> Self::Output {
                                    match self {
                                        Tuple(($($t,)*)) => {
                                            ($($t.parse(server),)*)
                                        }
                                    }
                                }
                            }
                    impl<$($T: Token),*> RawTuple for ($($T,)*) {
                        type LeafTuple = Tuple<($(Leaf<$T>,)*)>;
                        fn leaf_tuple() -> Self::LeafTuple {
                            Tuple(($($T::leaf(),)*))
                        }
                    }
                    impl<$($T: Parser),*> ParserTuple for ($($T,)*) {
                        type Tuple = Tuple<($($T,)*)>;
                        fn tuple(self) -> Self::Tuple {
                            Tuple(self)
                        }
                    }
                };
            }
            impl_tuple!();
            impl_tuple!(t1: T1);
            impl_tuple!(t1: T1, t2: T2);
            impl_tuple!(t1: T1, t2: T2, t3: T3);
            impl_tuple!(t1: T1, t2: T2, t3: T3, t4: T4);
            impl_tuple!(t1: T1, t2: T2, t3: T3, t4: T4, t5: T5);
            impl_tuple!(t1: T1, t2: T2, t3: T3, t4: T4, t5: T5, t6: T6);
            impl_tuple!(t1: T1, t2: T2, t3: T3, t4: T4, t5: T5, t6: T6, t7: T7);
            impl_tuple!(
                t1: T1,
                t2: T2,
                t3: T3,
                t4: T4,
                t5: T5,
                t6: T6,
                t7: T7,
                t8: T8
            );
        }
        trait Scanner: BufRead + Sized {
            fn tokenizer(self) -> Tokenizer<Self> {
                Tokenizer::new(self)
            }
        }
        impl<R: BufRead> Scanner for R {}
    }
    pub use self::i::{with_stdin, with_str};
    mod prelude {
        pub use super::i::{Parser, ParserTuple, RawTuple, Token, Usize1};
    }
}
// }}}