#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <cmath>
using namespace std;
using ll = long long;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    int n, k;
    cin >> n >> k;
    k = n - k;

    vector<int> a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }

    ll r = 1LL << 60;
    for (int h = 0; h < 2; h++) {
        int x = a[min(k + n / 2, n - 1)];
        ll t = 0;
        for (int i = 0; i < n; i++) {
            t += abs(x - a[i]) * (i < k ? -1 : 1);
        }
        r = min(r, t);

        reverse(a.begin(), a.end());
        for (int i = 0; i < n; i++) {
            a[i] *= -1;
        }
    }

    cout << r << endl;

    return 0;
}