#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define int ll
const int inf = 1e18;
const int N = 5e5 + 7;
int n, k, a[N], res;
int val1 = 0, val2 = 0;
multiset<int> q1, q2;
inline void add(int x)
{
    if (q2.size() == 0)
        q1.insert(x), val1 += x;
    else
    {
        int tmp = *q2.begin();
        if (x >= tmp)
            q2.insert(x), val2 += x;
        else
            q1.insert(x), val1 += x;
    }
    while (q1.size() > q2.size() + 1)
    {
        auto it = prev(q1.end());
        int tmp = *it;
        q1.erase(it), q2.insert(tmp);
        val1 -= tmp, val2 += tmp;
    }
    while (q1.size() < q2.size())
    {
        auto it = q2.begin();
        int tmp = *it;
        q2.erase(it), q1.insert(tmp);
        val2 -= tmp, val1 += tmp;
    }
}

inline void del(int x)
{
    if (q2.find(x) != q2.end())
        q2.erase(q2.find(x)), val2 -= x;
    else
        q1.erase(q1.find(x)), val1 -= x;
    while (q1.size() > q2.size() + 1)
    {
        auto it = prev(q1.end());
        int tmp = *it;
        q1.erase(it), q2.insert(tmp);
        val1 -= tmp, val2 += tmp;
    }
    while (q1.size() < q2.size())
    {
        auto it = q2.begin();
        int tmp = *it;
        q2.erase(it), q1.insert(tmp);
        val2 -= tmp, val1 += tmp;
    }
}
signed main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cin >> n >> k;
    for (int i = 1; i <= n; i++)
        cin >> a[i];
    for (int i = 1; i <= k; i++)
        add(a[i]);
    int val = *(q1.rbegin());
    res = val2 - val1 + (q1.size() - q2.size()) * val;
    for (int i = k + 1; i <= n; i++)
    {
        del(a[i - k]), add(a[i]);
        val = *(q1.rbegin());
        res = min(res, ll(val2 - val1 + (q1.size() - q2.size()) * val));
    }
    cout << res;
}