1 #include<cstdio>
 2 #include<algorithm>
 3 using namespace std;
 4 
 5 const int inf=0x3f3f3f3f;
 6 int dp[2005][1005];
 7 int v[2005];
 8 
 9 int main()
10 {
11     int n,k,i,j;
12     dp[0][0]=0;
13     while(scanf("%d%d",&n,&k)!=EOF)
14     {
15         for(i=1;i<=n;i++)
16         scanf("%d",&v[i]);
17         for(i=0;i<=n;i++)
18         for(j=1;j<=k;j++)
19         dp[i][j]=inf;
20         sort(v,v+n+1);
21         for(i=2;i<=n;i++)
22         {
23             for(j=1;j*2<=i;j++)
24             dp[i][j]=min(dp[i-2][j-1]+(v[i]-v[i-1])*(v[i]-v[i-1]),dp[i-1][j]);
25         }
26         printf("%d\n",dp[n][k]);
27     }
28     return 0;
29 }