hdu 1421

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <vector>
#include <queue>
#include <map>
#include <algorithm>
#include <set>
using namespace std;
#define MM(a) memset(a,0,sizeof(a))
typedef long long ll;
typedef unsigned long long ULL;
const int mod = 1000000007;
const double eps = 1e-10;
const int inf = 0x3f3f3f3f;
const int big=50000;
int max(int a,int b) {return a>b?a:b;};
int min(int a,int b) {return a<b?a:b;};
int a[2005],dp[2005][2005];
int main()
{int n,k;while(~scanf("%d %d",&n,&k)){for(int i=1;i<=n;i++)scanf("%d",&a[i]);sort(a+1,a+n+1);for(int i=0;i<=k;i++){dp[0][i]=0;dp[1][i]=inf;}for(int i=0;i<=n;i++)dp[i][0]=0;for(int i=2;i<=n;i++)for(int j=1;j<=k;j++)if(2*j>i)dp[i][j]=inf;elsedp[i][j]=min(dp[i-1][j],dp[i-2][j-1]+(a[i]-a[i-1])*(a[i]-a[i-1]));cout<<dp[n][k]<<endl;}return 0;
}