#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <cmath>
using namespace std;
inline int read() {
	int x, f = 1; char ch;
	while(ch = getchar(), !isdigit(ch))
		if(ch=='-')f=-1;x=ch-48;
	while(ch = getchar(), isdigit(ch))
		x = x*10 + ch - 48;
	return x*f;
}
int enemy[10004];
int main()
{
	int n, k, ans, fans;
	freopen("qwa.in","r",stdin);
	freopen("qwa.out","w",stdout);
	n = read();k = read();
	for(int i = 1; i <= k; i++)
		enemy[i] = read();
	sort(enemy,enemy+k+1);
	for(int i = 1; i <= n-k+1; i++){
		ans = 0;
		for(int j = i;j <= i+k-1; j++)
			for(int o = j+1; o <= i+k-1; o++)
				ans+=abs(enemy[j]-enemy[o]);
		fans = min(ans,fans);
	}
	printf("%d", fans);
	return 0;
}