#ifndef LOCAL
#include <bits/stdc++.h>

using namespace std;

#define debug(...) (void(0))
#else
#include "algo/debug.h"
#endif
template <class T>
struct MergeSortTree {
   private:
    int N;
    int sz;
    T mn, mx;
    std::vector<std::vector<T>> dat;
    std::vector<std::vector<T>> pref;
    int LB(const std::vector<T>& v, const T& x) const {
        return std::distance(v.begin(), std::lower_bound(v.begin(), v.end(), x));
    }

   public:
    MergeSortTree() = default;
    MergeSortTree(const std::vector<T>& v) : N((int)v.size()) {
        mn = std::numeric_limits<T>::max();
        mx = std::numeric_limits<T>::lowest();
        sz = (int)std::bit_ceil((unsigned int)N);
        dat.assign(2 * sz, {});
        pref.assign(2 * sz, {0});
        for (int i = 0; i < N; i++) {
            dat[i + sz].push_back(v[i]);
            pref[i + sz].push_back(v[i]);
            mn = std::min(mn, v[i]);
            mx = std::max(mx, v[i]);
        }
        for (int i = sz - 1; i >= 1; i--) {
            dat[i].resize(dat[2 * i].size() + dat[2 * i + 1].size());
            std::merge(dat[2 * i].begin(), dat[2 * i].end(), dat[2 * i + 1].begin(), dat[2 * i + 1].end(), dat[i].begin());

            pref[i].resize(dat[i].size() + 1);
            for (unsigned j{}; j < dat[i].size(); j++) {
                pref[i][j + 1] += pref[i][j] + dat[i][j];
            }
        }
    };
    int count_lt(int l, int r, const T& x) const {
        assert(0 <= l && l <= r && r <= N);
        l += sz;
        r += sz;
        int ans = 0;
        while (l < r) {
            if (l & 1) ans += LB(dat[l++], x);
            if (r & 1) ans += LB(dat[--r], x);
            l >>= 1;
            r >>= 1;
        }
        return ans;
    }
    int count_le(int l, int r, const T& x) const { return count_lt(l, r, x + 1); }
    int count_gt(int l, int r, const T& x) const { return r - l - count_le(l, r, x); }
    int count_ge(int l, int r, const T& x) const { return r - l - count_lt(l, r, x); }
    T kth(int l, int r, const T& k) const {
        T lo = mn, hi = mx + T{1};
        while (hi > lo + 1) {
            T mi = (lo + hi) >> 1;
            (count_lt(l, r, mi) <= k ? lo : hi) = mi;
        }
        return lo;
    }
    int64_t Solve(int l, int r, int K) const {
        int64_t val = kth(l, r, K / 2);
        int64_t cnt_lt = count_lt(l, r, val);
        int64_t cnt_ge = r - l - cnt_lt;
        l += sz;
        r += sz;
        int64_t sum_lt = 0;
        int64_t sum_all = 0;
        while (l < r) {
            if (l & 1) {
                int k = LB(dat[l], val);
                sum_lt += pref[l][k];
                sum_all += pref[l][dat[l].size()];
                l++;
            }
            if (r & 1) {
                r--;
                int k = LB(dat[r], val);
                sum_lt += pref[r][k];
                sum_all += pref[r][dat[r].size()];
            }
            l >>= 1;
            r >>= 1;
        }
        int64_t sum_ge = sum_all - sum_lt;
        return val * (cnt_lt - cnt_ge) + sum_ge - sum_lt;
    }
};
void solve() {
    int N, K;
    cin >> N >> K;
    vector<int64_t> A(N);
    for (int i = 0; i < N; i++) cin >> A[i];
    MergeSortTree<int64_t> freq(A);
    int64_t ans = 1e18;
    for (int i = 0; i + K <= N; i++) {
        ans = min(ans, freq.Solve(i, i + K, K));
    }
    cout << ans << endl;
}

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    int tt = 1;
    // std::cin >> tt;
    while (tt--) {
        solve();
    }
}