#include <bits/stdc++.h>
#include <sys/time.h>
using namespace std;

#define rep(i,n) for(long long i = 0; i < (long long)(n); i++)
template<class T1, class T2> bool chmin(T1 &a, T2 b) { return b < a && (a = b, true); }
template<class T1, class T2> bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }

using ll = long long; using vll = vector<ll>; using vvll = vector<vll>; using P = pair<ll, ll>;

static const long long INF = 1e18;

/*****************/
// Dictionary
/*****************/
// Nはバケット数
template<int N> class FID {
    static const int bucket = 512, block = 16;
    // 整数iのpopcountをO(1)で求めるためのテーブル
    // popcount[i] = __builtin_popcount(i), i<65536
    static char popcount[];

    // B[i]: s[0:512*i)のビット1の総数
    int n, B[N/bucket+10];
    // bs[i]: s[16*i:16*(i+1)]のビット列そのもの
    unsigned short bs[N/block+10] = {};

    // b[i]: s[i/32*512:i/32*512+i%32*32)のビット1の総数 
    // bs[i]を512bitずつリセットしながら、累積和を取ってる感じ。
    unsigned short b[N/block+10] = {};

public:
    FID(){}
    FID(int n, bool s[]) : n(n) {
        if(!popcount[1]) for (int i = 0; i < (1<<block); i++) popcount[i] = __builtin_popcount(i);

        bs[0] = B[0] = b[0] = 0;
        for (int i = 0; i < n; i++) {
            if(i%block == 0) {
                bs[i/block+1] = 0;
                if(i%bucket == 0) {
                    B[i/bucket+1] = B[i/bucket];
                    b[i/block+1] = b[i/block] = 0;
                }
                else b[i/block+1] = b[i/block];
            }
            bs[i/block]   |= short(s[i])<<(i%block);
            b[i/block+1]  += s[i];
            B[i/bucket+1] += s[i];
        }
        if(n%bucket == 0) b[n/block] = 0;
    }

    // number of val in [0,r), O(1)
    // 大ブロックの累積和(512bit)+中ブロックの累積和(16bit)+「余り分に適切なbitmaskをかけてpopcount」
    int count(bool val, int r) { return val? B[r/bucket]+b[r/block]+popcount[bs[r/block]&((1<<(r%block))-1)]: r-count(1,r); }
    // number of val in [l,r), O(1)
    int count(bool val, int l, int r) { return count(val,r)-count(val,l); }

    // position of ith in val, 0-indexed, O(log n)
    // 範囲外を示していたら-1を返す
    int select(bool val, int i) {
        if(i < 0 or count(val,n) <= i) return -1;
        i++;
        int lb = 0, ub = n, md;
        while(ub-lb>1) {
            md = (lb+ub)>>1;
            if(count(val,md) >= i) ub = md;
            else lb = md;
        }
        return ub-1;
    }
    int select(bool val, int i, int l) { return select(val,i+count(val,l)); }
};
template<int N> char FID<N>::popcount[1<<FID<N>::block];

/*****************/
// Wavelet Matrix
/*****************/
// 長さNで、値域[0, m=2^D)の整数を管理する
template<class T, int N, int D> class wavelet {
    int n, zs[D];
    FID<N> dat[D];
    T raw_data[D+1][N] = {};
    T sum_data[D+1][N+1] = {};

public:
    wavelet(int n, T seq[]) : n(n) {
        T l[N] = {}, r[N] = {};
        bool b[N] = {};
        memcpy(raw_data[0], seq, sizeof(T)*n);
        for (int d = 0; d < D; d++) {
            int lh = 0, rh = 0;
            for (int i = 0; i < n; i++) {
                b[i] = (raw_data[d][i]>>(D-d-1))&1;
                if(b[i]) r[rh++] = raw_data[d][i];
                else l[lh++] = raw_data[d][i];
            }
            dat[d] = FID<N>(n,b);
            zs[d] = lh;
            swap(l,raw_data[d+1]);
            memcpy(raw_data[d+1]+lh, r, rh*sizeof(T));
        }
        rep(d, D+1) rep(i, N) sum_data[d][i+1] = sum_data[d][i] + raw_data[d][i];
    }
    // 深さdでの列の[l, r)での累積和を求める
    T getSum(int d, int l, int r) {
        return sum_data[d][r] - sum_data[d][l];
    }

    // rank: 区間[0,r)にあるvalの個数
    // O(log m)
    int count(T val, int l, int r) {
        for (int d = 0; d < D; d++) {
            // ここで[l, r)にxのd桁目までが全て入っていることを保証(d>0)
            bool b = (val>>(D-d-1))&1;
            l = dat[d].count(b,l)+b*zs[d];
            r = dat[d].count(b,r)+b*zs[d];
        }
        return r-l;
    }
    int count(T val, int r) { return count(val,0,r); }

    // k is 0-indexed!!!!
    // kth_number: 区間[l,r)でk番目に大きい数
    // O(log m)
    T kth_number(int l, int r, int k) {
        if(r-l <= k or k < 0) return -1;
        T ret = 0;
        for (int d = 0; d < D; d++) {
            int lc = dat[d].count(1,l), rc = dat[d].count(1,r);
            // lc - rc = [l, r)で立っている1の数
            if(rc-lc > k) { // 1の数にkが収まっていれば
                l = lc+zs[d], r = rc+zs[d]; // 1側に遷移
                ret |= 1ULL<<(D-d-1);
            } else { // 0側ならば
                k -= rc-lc; // 1側にあった数だけkを削って次へ
                l -= lc, r -= rc;
            }
        }
        return ret;
    }

    // number of elements in [l,r) in [a,b)
    // O(log m)
    int freq_dfs(int d, int l, int r, T val, T a, T b) {
        if(l == r) return 0;
        if(d == D) return (a <= val and val < b)? r-l: 0;
        T nv = 1ULL<<(D-d-1)|val, nnv = ((1ULL<<(D-d-1))-1)|nv;
        if(nnv < a or b <= val) return 0;
        if(a <= val and nnv < b) return r-l;
        int lc = dat[d].count(1,l), rc = dat[d].count(1,r);
        return freq_dfs(d+1,l-lc,r-rc,val,a,b)+
            freq_dfs(d+1,lc+zs[d],rc+zs[d],nv,a,b);
    }
    int freq(int l, int r, T a, T b) { return freq_dfs(0,l,r,0,a,b); }

    // get sum of elements in [l,r) in [a,b)
    // O(log m)
    T sum_dfs(int d, int l, int r, T val, T a, T b) {
        // Wavelet Matrixの深さdで、
        // [l, r)が[val, nv) = [val, val+(1ll<<(D-d)))の値域を表現している時、
        // [a, b)の値域のものの和は？

        if(l == r) return 0; // valは無いので0を返す
        if(d == D) return (a <= val and val < b)? (r-l)*val: 0; // 深さDでは全部の値が同じなので、そのままかけて返す

        T nv = 1ULL<<(D-d-1)|val, nnv = ((1ULL<<(D-d-1))-1)|nv;
        if(nnv < a or b <= val) // どんなに1を選んでもaに満たなかったり、すでに最大を超えていたら0
            return 0; 
        if (a <= val and nnv < b) // これからどう選んでも a <= [l, r) < bの場合、累積和を返す
            return getSum(d, l, r); 

        int lc = dat[d].count(1,l), rc = dat[d].count(1,r);
        return sum_dfs(d+1,l-lc,r-rc,val,a,b)+ sum_dfs(d+1,lc+zs[d],rc+zs[d],nv,a,b);
    }
    T sum(int l, int r, T a, T b) { return sum_dfs(0,l,r,0,a,b); }
};


#define MAXN 100010
#define MAXK 30
int main(void) {
    ll n, k; cin >> n >> k; assert(1<=k&&k<=n&&n<=100000);
    ll a[MAXN]; rep(i, n) { cin >> a[i]; assert(1<=a[i]&&a[i]<=1e9); }
    wavelet<ll, MAXN, MAXK> w(n, a);

    ll ret = INF;
    rep(i, n-k+1) {
        ll val = w.kth_number(i, i+k, k/2);

        ll less_than_sum = w.sum(i, i+k, 0, val);
        ll more_than_sum = w.sum(i, i+k, val+1, (1ll<<MAXK)-1);
        ll less_than_freq = w.freq(i, i+k, 0, val);
        ll more_than_freq = w.freq(i, i+k, val+1, (1ll<<MAXK)-1);

        ll tmp = abs(more_than_sum - more_than_freq * val) + abs(less_than_sum - less_than_freq * val);
        chmin(ret, tmp);
    }
    cout << ret << endl;

    return 0;
}