using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    static int[] LList(long n) => Enumerable.Repeat(0, (int)n).Select(_ => int.Parse(ReadLine())).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var c = NList;
        var (n, k) = (c[0], c[1]);
        var a = NList;
        var cum = new long[n + 1];
        for (var i = 0; i < n; ++i) cum[i + 1] = cum[i] + a[i];
        var ans = long.MaxValue;
        if (k == 0)
        {
            ans = Math.Min(a[0] * (long)n - cum[n], cum[n] - a[^1] * (long)n);
        }
        else if (k == n)
        {
            ans = a[n / 2] * (long)n / 2 - cum[n / 2] + cum[n] - cum[n / 2] - a[n / 2] * (long)(n - n / 2);
        }
        else
        {
            var pos = (2 * k - n - 1) / 2;
            for (var i = 0L; i <= n - k; ++i)
            {
                var x = Math.Max(0L, Math.Min(n - 1, pos));
                ans = Math.Min(ans, cum[i] - a[x] * i + a[x] * (x - i) - (cum[x] - cum[i])
                    + cum[k + i] - cum[x] - a[x] * (k + i - x) + a[x] * (n - k - i) - cum[n] + cum[k + i]);
                pos += 2;
            }
        }
        WriteLine(ans);
    }
}