#include <iostream>

 #include <cstring>

 #include<vector>

 #include<string>

 #include <cmath>

 #include <map>

 #include <queue>

 #include <algorithm>

 using namespace std;

 #define inf (1LL << 31) - 1

 #define rep(i,j,k) for(int i = (j); i <= (k); i++)

 #define rep__(i,j,k) for(int i = (j); i < (k); i++)

 #define per(i,j,k) for(int i = (j); i >= (k); i--)

 #define per__(i,j,k) for(int i = (j); i > (k); i--)

 const int N = ;

 int mv_x[] = { , , , - };

 int mv_y[] = { , -, ,  };

 int x[]; //草的x

 int y[]; //草的y

 int l;  //几颗草

 char mp[N][N];  //原始地图

 char cp_mp[N][N]; //原始地图副本，用于bfs

 bool vis[N][N];

 int ans; //答案

 int n, m;

 struct node{

     int x, y, c;

     node(){}

     node(int o, int oo, int ooo){

         x = o;

         y = oo;

         c = ooo;

     }

 };

 inline void input(){

     l = ;

     rep(i, , n) rep(j, , m){

         cin >> mp[i][j];

         //记录下所有草

         if (mp[i][j] == '#'){

             x[l] = i;

             y[l++] = j;

         }

     }

 }

 //每种情况前，初始化函数

 inline void init_vis_And_cp_mp(){

     memset(vis, , sizeof(vis));

     memcpy(cp_mp, mp, sizeof(mp));

 }

 //边界

 inline bool check(int x, int y){

     return x >=  && x <= n && y >=  && y <= m;

 }

 //检查草是否都烧完

 bool all_Fired(){

     rep(i, , n) rep(j, , m){

         if (cp_mp[i][j] == '#' && !vis[i][j]) return false;

     }

     return true;

 }

 void bfs(int x1, int y1, int x2, int y2){

     queue<node> que;

     //标记两个点火源

     vis[x1][y1] = true;

     vis[x2][y2] = true;

     //放入队列

     node a1(x1, y1, );

     node a2(x2, y2, );

     que.push(a1);

     que.push(a2);

     int tmp_ans = ;

     while (!que.empty()){

         node tmp = que.front();

         que.pop();

         tmp_ans = max(tmp_ans, tmp.c); //这里是得出能烧到的草的最后时间

         rep__(p, , ){

             int dx = tmp.x + mv_x[p];

             int dy = tmp.y + mv_y[p];

             //没越界，没被访问过，是草

             if (check(dx, dy) && !vis[dx][dy] && cp_mp[dx][dy] == '#'){

                 vis[dx][dy] = true;

                 node k(dx, dy, tmp.c + );

                 que.push(k);

             }

         }

     }

     //全部烧完才能算一个答案

     if (all_Fired()) ans = min(ans, tmp_ans);

 }

 int main(){

     ios::sync_with_stdio(false);

     cin.tie();

     int T;

     cin >> T;

     rep(o, , T){

         cin >> n >> m;

         input();

         ans = inf; //

         //枚举点火情况

         rep__(i, , l ) rep__(j, i, l){

             init_vis_And_cp_mp(); //每种情况前，初始化函数

             bfs(x[i], y[i], x[j], y[j]);  //两个点火源

         }

     //    cout << "Case 1: 1" << endl;

         cout << "Case " << o << ": " << (ans == inf ? - : ans) << endl;

     }

     return ;

 }