#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <cmath>
#include <stdio.h>
#include <queue>
#include <deque>
#include <cstdio>
#include <set>
#include <map>
#include <bitset>
#include <stack>
#include <cctype>
using namespace std;
long long a[200020];
int main() {
	long n, k;
	cin >> n >> k;
	for (int i = 0; i < n; i++) {
		cin >> a[i];
	}
	long long co = 0, co1 = 0;
	for (long i = 0; i < n; i++) {
		if (i < k) {
			co += abs(a[0] - a[i]);
		}
		else{
			co -= abs(a[0] - a[i]);
		}
	}
	for (long i = n - 1; i >= 0; i--) {
		if ((n - i - 1) < k) {
			co1 += abs(a[n - 1] - a[i]);
		}
		else {
			co1 -= abs(a[n - 1] - a[i]);
		}
	}
	long long ans = min(co, co1);
	if (k == n) {
		long long sum = 0;
		for (int i = 0; i < n; i++) {
			sum += abs(a[i] - a[n / 2]);
		}
		ans = min(ans, sum);
	}
	cout << ans << endl;
	return 0;
}