#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
int a[100001];
int n,k,MIN;
int b[100001];
int main()
{   
    freopen("qwa.in","r",stdin);
    freopen("qwa.out","w",stdout);
	cin>>n>>k;
	for(int i=1;i<=n;i++)
	{
		cin>>a[i];
	}
	// for(int i=1;i<=n;i++)cout<<b[i]<<" ";
	 //cout<<endl;
	   sort(a+1,a+n+1);
	   //for(int i=1;i<=n;i++)cout<<a[i]<<" ";
	   //cout<<endl;
	 for(int i=1;i<=n;i++)b[i]+=b[i-1]+a[i];
	  MIN=999999;
	 for(int i=1;i<=n+1-k;i++)
	 {   
	      int ans=0;
	      int js=k;
	      int zong=0;
	 	  zong=b[i+k-1]-b[i-1];
		 for(int j=i;j<i+k;j++)
		 {
		 	ans+=zong-js*a[j];
		 	zong-=a[j];
		 	js-=1;
		 	//cout<<"Z"<<" "<<zong<<endl;
		 	//cout<<"A"<<" "<<ans<<endl;
		 }
		  MIN=min(ans,MIN); 
		  //cout<<"M"<<" "<<MIN<<endl;   
	  } 
	  cout<<MIN<<endl;
	  return 0; 
	
 }