#include<cstdio>
#include<iostream>
#include<cmath>
#include<algorithm>
using namespace std;
int n, k;
int vv[50010];
int zz[25010];
int js(int);
int main()
{
	freopen("qwa.in", "r", stdin);
	freopen("qwa.out", "w", stdout);
	int i, j, q;
	cin>>n>>k;
	if(n==0||k==0) 
	{
		cout<<"0"<<endl;
		return 0;
	}
	for(i=1; i<=n; i++)
		cin>>vv[i];
	sort(vv+1,vv+n+1);
	for(i=1; i<=n; i++)
	{
		if(i+k==n+2)
			break;	
		else
			js(i-1);
	}
	sort(zz+1, zz+n-k+1);
	cout<<zz[1]<<endl;
	return 0;
}
int js(int x)
{
	int i, j;
	int tt;
	for(i=1; i<k; i++)
		for(j=1; i+j<=k; j++)
			zz[x+1]+=abs(vv[x+i]-vv[x+i+j]);
}