#include <cstdio>

#include <cstring>

#include <string>

#include <cmath>

#include <iostream>

#include <algorithm>

#include <queue>

#include <cstdlib>

#include <stack>

#include <vector>

#include <set>

#include <map>

#define LL long long

#define mod 10007

#define inf 0x3f3f3f3f

#define N 100010

#define FILL(a,b) (memset(a,b,sizeof(a)))

#define lson l,m,rt<<1

#define rson m+1,r,rt<<1|1

using namespace std;

const int maxnode=;

const int MaxN=;

const int MaxM=;

int k;

struct DLX

{

    int n,m,size;

    int U[maxnode],D[maxnode],R[maxnode],L[maxnode],Row[maxnode],Col[maxnode];

    int  H[MaxN],S[MaxM];

    int ansd,ans[MaxN];

    void init(int _n,int _m)

    {

        n=_n;m=_m;

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

        {

            S[i]=;

            U[i]=D[i]=i;

            L[i]=i-;

            R[i]=i+;

        }

        R[m]=;L[]=m;

        size=m;

        for(int i=;i<=n;i++)H[i]=-;

    }

    void Link(int r,int c)

    {

        ++S[Col[++size]=c];

        Row[size]=r;

        D[size]=D[c];

        U[D[c]]=size;

        U[size]=c;

        D[c]=size;

        if(H[r]<)H[r]=L[size]=R[size]=size;

        else

        {

            R[size]=R[H[r]];

            L[R[H[r]]]=size;

            L[size]=H[r];

            R[H[r]]=size;

        }

    }

   void Remove(int c)

    {

        for(int i = D[c];i != c;i = D[i])

            L[R[i]] = L[i], R[L[i]] = R[i];

    }

    void Resume(int c)

    {

        for(int i = U[c];i != c;i = U[i])

            L[R[i]]=R[L[i]]=i;

    }

    bool vis[maxnode];

    int h()

    {

        int res=;

        for(int c=R[];c!=;c=R[c])vis[c]=true;

        for(int c=R[];c!=;c=R[c])

        if(vis[c])

        {

            res++;

            vis[c]=false;

            for(int i=D[c];i!=c;i=D[i])

                for(int j=R[i];j!=i;j=R[j])

                    vis[Col[j]]=false;

        }

        return res;

    }

    bool Dance(int d)//d为递归深度

    {

        if(d+h()>k)return false;

        if(R[]==)//找到解

            return d<=k;

        //找S最小的C列

        int c=R[];//第一个未删除的列

        for(int i=R[];i!=;i=R[i])

            if(S[i]<S[c])c=i;

        for(int i=D[c];i!=c;i=D[i])//用结点i所在的行覆盖第c列

        {

            Remove(i);

            for(int j=R[i];j!=i;j=R[j])Remove(j);//删除节结点i所在行覆盖第c列

            if(Dance(d+))return true;

            for(int j=L[i];j!=i;j=L[j])Resume(j);// 恢复

            Resume(i);

        }

        return false;

    }

};

DLX g;

struct node

{

    LL x,y;

}c[MaxN];

LL dist(node a,node b)

{

    return (LL)((LL)abs(a.x-b.x)+(LL)abs(a.y-b.y));

}

int main()

{

    int T,n,cas=;

    int mnx,mxx,mny,mxy;

    scanf("%d",&T);

    while(T--)

    {

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

        for(int i=;i<=n;i++)scanf("%I64d%I64d",&c[i].x,&c[i].y);

        LL l=,r=1000000000000LL,ans;

        while(l<=r)

        {

            LL mid=(l+r)/;

            g.init(n,n);

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

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

                if(dist(c[i],c[j])<=mid)

                    g.Link(i,j);

            if(g.Dance())r=mid-,ans=mid;

            else l=mid+;

        }

        printf("Case #%d: %I64d\n",cas++,ans);

    }

}