#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(ll i=0;i<n;i++)
#define repl(i,l,r) for(ll i=(l);i<(r);i++)
#define per(i,n) for(ll i=(n)-1;i>=0;i--)
#define perl(i,r,l) for(ll i=r-1;i>=l;i--)
#define fi first
#define se second
#define pb push_back
#define ins insert
#define pqueue(x) priority_queue<x,vector<x>,greater<x>>
#define all(x) (x).begin(),(x).end()
#define CST(x) cout<<fixed<<setprecision(x)
#define vtpl(x,y,z) vector<tuple<x,y,z>>
#define rev(x) reverse(x);
using ll=long long;
using vl=vector<ll>;
using vvl=vector<vector<ll>>;
using pl=pair<ll,ll>;
using vpl=vector<pl>;
using vvpl=vector<vpl>;
const ll MOD=1000000007;
const ll MOD9=998244353;
const int inf=1e9+10;
const ll INF=4e18;
const ll dy[9]={0,-1,0,1,1,1,-1,-1,0};
const ll dx[9]={-1,0,1,0,1,-1,1,-1,0};
template<class T> inline bool chmin(T& a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template<class T> inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}

template<typename U = unsigned, int B = 32>
class binary_trie {
    struct node {
        int cnt;
        node *ch[2];
        node() : cnt(0), ch{ nullptr, nullptr } {}
    };
    node* add(node* t, U val, int b = B - 1) {
        if (!t) t = new node;
        t->cnt += 1;
        if (b < 0) return t;
        bool f = (val >> (U)b) & (U)1;
        t->ch[f] = add(t->ch[f], val, b - 1);
        return t;
    }
    node* sub(node* t, U val, int b = B - 1) {
        assert(t);
        t->cnt -= 1;
        if (t->cnt == 0) return nullptr;
        if (b < 0) return t;
        bool f = (val >> (U)b) & (U)1;
        t->ch[f] = sub(t->ch[f], val, b - 1);
        return t;
    }
    U get_min(node* t, U val, int b = B - 1) const {
        assert(t);
        if (b < 0) return 0;
        bool f = (val >> (U)b) & (U)1; f ^= !t->ch[f];
        return get_min(t->ch[f], val, b - 1) | ((U)f << (U)b);
    }
    U get(node* t, int k, int b = B - 1) const {
        if (b < 0) return 0;
        int m = t->ch[0] ? t->ch[0]->cnt : 0;
        return k < m ? get(t->ch[0], k, b - 1) : get(t->ch[1], k - m, b - 1) | ((U)1 << (U)b);
    }
    int count_lower(node* t, U val, int b = B - 1) {
        if (!t || b < 0) return 0;
        bool f = (val >> (U)b) & (U)1;
        return (f && t->ch[0] ? t->ch[0]->cnt : 0) + count_lower(t->ch[f], val, b - 1);
    }
    node *root;
public:
    binary_trie() : root(nullptr) {}
    int size() const {
        return root ? root->cnt : 0;
    }
    bool empty() const {
        return !root;
    }
    void insert(U val) {
        root = add(root, val);
    }
    void erase(U val) {
        root = sub(root, val);
    }
    U max_element(U bias = 0) const {
        return get_min(root, ~bias);
    }
    U min_element(U bias = 0) const {
        return get_min(root, bias);
    }
    int lower_bound(U val) { // return id
        return count_lower(root, val);
    }
    int upper_bound(U val) { // return id
        return count_lower(root, val + 1);
    }
    U operator[](int k) const {
        assert(0 <= k && k < size());
        return get(root, k);
    }
    int count(U val) const {
        if (!root) return 0;
        node *t = root;
        for (int i = B - 1; i >= 0; i--) {
            t = t->ch[(val >> (U)i) & (U)1];
            if (!t) return 0;
        }
        return t->cnt;
    }
};

//0-indexed,2冪のセグメントツリー
template <class T>
struct SegTree {
    private:
    int n;// 葉の数
    vector<T> data;// データを格納するvector
    T def; // 初期値かつ単位元
    function<T(T, T)> operation; // 区間クエリで使う処理
    function<T(T, T)> change;// 点更新で使う処理

    T find(int a, int b) {
        T val_left = def, val_right = def;
        for (a += (n - 1), b += (n - 1); a < b; a >>= 1, b >>= 1)
        {
            if ((a & 1) == 0){
                val_left = operation(val_left, data[a]);
            }
            if ((b & 1) == 0){
                val_right = operation(data[--b],val_right);
            }
        }
        return operation(val_left, val_right);
    }
    public:
    // _n:必要サイズ, _def:初期値かつ単位元, _operation:クエリ関数,
    // _change:更新関数
    SegTree(size_t _n, T _def, function<T(T, T)> _operation,
        function<T(T, T)> _change=[](T a,T b){return b;})
        : def(_def), operation(_operation), change(_change) {
        n = 1;
        while (n < _n) {
            n *= 2;
        }
        data = vector<T>(2 * n - 1, def);
    }
    void set(int i, T x) { data[i + n - 1] = x; }
    void build() {
        for (int k=n-2;k>=0;k--) data[k] = operation(data[2*k+1],data[2*k+2]);
    }
    // 場所i(0-indexed)の値をxで更新
    void update(int i, T x) {
        i += n - 1;
        data[i] = change(data[i], x);
        while (i > 0) {
            i = (i - 1) / 2;
            data[i] = operation(data[i * 2 + 1], data[i * 2 + 2]);
        }
    }
    T all_prod(){
      return data[0];
    }
    // [a, b)の区間クエリを実行
    T query(int a, int b) {
        //return _query(a, b, 0, 0, n);
        return find(a,b);
    }

    // 添字でアクセス
    T operator[](int i) {
        return data[i + n - 1];
    }
};

int main(){
  ll n,k;cin >> n >> k;
  vl v(n);rep(i,n)cin >> v[i];
  vl pls=v;sort(all(pls));pls.erase(unique(all(pls)),pls.end());
  rep(i,n)v[i]=lower_bound(all(pls),v[i])-pls.begin();
  binary_trie<ll> bt;
  ll m=pls.size();
  SegTree<pl> st(m,{0,0},[](pl a,pl b){return make_pair(a.first+b.first,a.second+b.second);},[](pl a,pl b){return make_pair(a.first+b.first,a.second+b.second);});
  rep(i,k){
    bt.insert(v[i]);
    st.update(v[i],{pls[v[i]],1});
  }
  ll ans=INF;
  rep(i,n-k+1){
    ll mid=bt[k/2];
    auto f=st.query(mid,m);
    ll ret=f.first-pls[mid]*f.second;
    auto g=st.query(0,mid);
    ret+=pls[mid]*g.second-g.first;
    chmin(ans,ret);
    if(i==n-k)break;
    bt.erase(v[i]);
    st.update(v[i],{-pls[v[i]],-1});
    bt.insert(v[k+i]);
    st.update(v[k+i],{pls[v[k+i]],1});
  }
  cout << ans << endl;
}