/*

     最小生成树(Kruskal)：以权值为头，带入两个端点，自然的排序;感觉结构体的并查集很好看

     注意：题目老头要的是两个农田的高度差，中文水平不好，题意理解成和平均值的高度差！

 */

 #include <cstdio>

 #include <algorithm>

 #include <cstring>

 #include <cmath>

 #include <vector>

 #include <queue>

 #include <set>

 using namespace std;

 const int MAXN = 1e3 + ;

 const int MAXM = 1e2 + ;

 const int INF = 0x3f3f3f3f;

 int n, m;

 int a[MAXN][MAXN];

 vector<pair<int, int> > G[MAXM];

 struct UF

 {

     int rt[MAXN*MAXN];

     void init(void)    {memset (rt, -, sizeof (rt));}

     int Find(int x)    {return (rt[x] == -) ? x : rt[x] = Find (rt[x]);}

     void Union(int x, int y)

     {

         x = Find (x);    y = Find (y);

         if (x > y)    rt[y] = x;

         else if (x < y)    rt[x] = y;

     }

     bool same(int x, int y)    {return Find (x) == Find (y);}

 }uf;

 int Kruskal(void)

 {

     uf.init ();

     int ans = ;

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

     {

         for (int j=; j<G[i].size (); ++j)

         {

             int u = G[i][j].first;    int v = G[i][j].second;

             if (!uf.same (u, v))    {uf.Union (u, v);    ans += i;}

         }

     }

     return ans;

 }

 int get_id(int i, int j)    {return (i - ) * m + j;}

 int main(void)        //2015百度之星初赛2 HDOJ 5253 连接的管道

 {

     int t, cas = ;    scanf ("%d", &t);

     while (t--)

     {

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

         for (int i=; i<=; ++i)    G[i].clear ();

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

         {

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

             {

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

                 if (i > )    {G[abs (a[i][j] - a[i-][j])].push_back (make_pair (get_id (i, j), get_id (i-, j)));}

                 if (j > )    {G[abs (a[i][j] - a[i][j-])].push_back (make_pair (get_id (i, j), get_id (i, j-)));}

             }

         }

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

         printf ("%d\n", Kruskal ());

     }

     return ;

 }

 /*

 2

 4  3

 9 12 4

 7 8 56

 32 32 43

 21 12 12

 2  3

 34 56 56

 12 23 4

 */