//qwa.cpp
//ByHoohan
#include<iostream>
#include<cstdio>
#include<cmath>
#include<algorithm>
#include<cstring>
#include<cstdlib>
using namespace std;
 
int n,k,ans=2147483647;
int em[10010]; 
 
int main()
{
	freopen("qwa.in","r",stdin);
	freopen("qwa.out","w",stdout);
	cin>>n>>k;
	for(int i=1;i<=n;i++) cin>>em[i];
	sort(em+1,em+n+1); 
	for(int i=1;i<=n;i++)
	{
		int j=i+k;
		ans=min(abs(em[i]-em[j]),ans);
	}
	cout<<ans*2<<endl;
	return 0;
}