#include<bits/stdc++.h>
#define LL long long
#define N ((int)6e4 + 5)
#define MOD ((int)998244353 + 0)
#define MAX ((int)1e9 + 7)
#define MAXL ((ll)1e18 + 7)
#define MAXP ((int)1e3 + 7)
#define thr 1e-8
#define pi acos(-1)  /// pi = acos ( -1 )
#define fastio ios_base::sync_with_stdio(false),cin.tie(NULL)
#define endl "\n"

using namespace std;


string str[102];

int dxx[] = {-1,0,1,0}; /// dxx[3] , dyy[3] -> left
int dyy[] = {0,1,0,-1};



int dis[100][100];

bool IsValid(int row , int col)
{
    if(min(row , col) < 0 || row >= n || col >= m || str[row][col] == '#' || str[row][col] == 'm') return 0;
}

void bfs(int row , int col){
    memset(dis,-,sizeof dis);
    queue < pair < int , int > > que;
    que.push({row , col});
   // vis[row][col] = 1;
    dis[row][col] = 0;
    while(!que.empty()){
        int row = que.front().first , col = que.front().second;
        que.pop();
        for(int i = 0 ; i < 4 ; i++){
            int x = row + dxx[i] , y = col + dyy[i];
            if(IsValid(x,y) && dis[x][y] == -){
                dis[x][y] = dis[row][col] + 1;
                que.push({x,y});
            }
        }
    }
}



int main()
{

    /// problem: https://lightoj.com/problem/power-puff-girls
    int t;
    cin>>t;
    while(t--){
        int n , m;
        cin>>n>>m;
        for(int i = 0 ; i < n ; i++){
            cin>>str[i];
        }
        for(int i = 0 ; i < n ; i++){
            for(int j = 0 ; j < m ; j++){
                if(str[i][j] == 'h') bfs(i , j);
            }
        }
        int ans = 0;
        for(int i = 0 ; i < n ; i++){
            for(int j = 0 ; j < m ; j++){
                if(str[i][j] >= 'a' && str[i][j] <= 'c') ans = max(ans , dis[i][j]);
            }
        }
        cout<<ans<<endl;
    }

    return 0;
}