#include<cstdio>

#include<cstring>

#include<algorithm>

#include<queue>

#define maxn 10005

#define maxm 5005

using namespace std;

int dp[maxn][maxm];

int q[maxn*];

int num[maxn];

bool check(int j,int tail,int i)

{

    int yk=dp[q[tail-]][j-]+num[q[tail-]+]*num[q[tail-]+];

    int yj=dp[q[tail]][j-]+num[q[tail]+]*num[q[tail]+];

    int yi=dp[i][j-]+num[i+]*num[i+];

    int xk=*num[q[tail-]+];

    int xj=*num[q[tail]+];

    int xi=*num[i+];

    if((yi-yk)*(xj-xk)<=(yj-yk)*(xi-xk))return ;

    return ;

}

bool get(int head,int j,int i)

{

    int y1=dp[q[head]][j-]+num[q[head]+]*num[q[head]+];

    int y2=dp[q[head+]][j-]+num[q[head+]+]*num[q[head+]+];

    int x1=num[q[head]+];

    int x2=num[q[head+]+];

    if((y2-y1)<=*num[i]*(x2-x1))return ;

    return ;

}

int main()

{

    int n,m,t;

    int ca=;

    scanf("%d",&t);

    while(t--)

    {

        scanf("%d%d",&n,&m);

        for(int i=;i<=n;i++)scanf("%d",&num[i]);

        sort(num+,num+n+);

        int tail,head;

        for(int i=;i<=n;i++)

            dp[i][]=(num[i]-num[])*(num[i]-num[]);

        for(int j=;j<=m;j++)

        {

            head=tail=;

            q[++tail]=j-;

            for(int i=j;i<=n;i++)

            {

                while(tail-head>&&check(j,tail,i))tail--;

                q[++tail]=i;

                while(tail-head>&&get(head+,j,i))head++;

                int best=q[head+];

                dp[i][j]=dp[best][j-]+(num[i]-num[best+])*(num[i]-num[best+]);

            }

        }

        printf("Case %d: %d\n",ca++,dp[n][m]);

    }

    return ;

}

#include<cstdio>

#include<cstring>

#include<algorithm>

#define maxn 10005

#define maxm 5005

#define inf 99999999

using namespace std;

int dp[maxn][maxm];

int s[maxn][maxm];

int num[maxn];

int main()

{

    int n,m;

    int t,ca=;

    scanf("%d",&t);

    while(t--)

    {

        scanf("%d%d",&n,&m);

        for(int i=; i<=n; i++)

            scanf("%d",&num[i]);

        sort(num+,num++n);

        dp[][]=;

        for(int i=; i<=n; i++)

        {

            dp[i][]=(num[i]-num[])*(num[i]-num[]);

        }

        for(int j=; j<=m; j++)

        {

            s[n+][j]=n-;

            for(int i=n; i>=j; i--)

            {

                dp[i][j]=inf;

                for(int k=s[i][j-]; k<=s[i+][j]; k++)

                {

                    int tmp=dp[k][j-]+(num[i]-num[k+])*(num[i]-num[k+]);

                    if(dp[i][j]>tmp)

                    {

                        s[i][j]=k;

                        dp[i][j]=tmp;

                    }

                }

            }

        }

        printf("Case %d: %d\n",ca++,dp[n][m]);

    }

    return ;

}