/*
*Copyright (c) Swadheen Islam Robi (SIR01)
*Created on Tue Dec 10 2024 3:07:03 PM
*/
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ld long double
#define pie 2*(acos(0.0))
#define yes cout<<"YES\n"
#define no cout<<"NO\n"
#define pb push_back
#define endl "\n"
#define lcm(a,b) (a*b)/(__gcd<ll>(a,b))
#define mod 1000000007
#define srt(v) sort(v.begin(),v.end())
#define rsrt(v) sort(v.rbegin(),v.rend())
#define ALLAHU_AKBAR ios::sync_with_stdio(false); cin.tie(nullptr);
void sir()
{
// int y
ll n,m; cin>>n>>m;
char grid[n+1][m+1];
bool got = false;
ll cp = 0;
for(ll i=1; i<=n; i++)
{
for(ll j=1; j<=m; j++)
{
cin>>grid[i][j];
if(grid[i][j]=='+')got = true;
}
}
if(!got){
cout<<0<<endl;
return;
}
vector<pair<ll,ll>>v;
for(ll i=1; i<n; i++)
{
for(ll j=1; j<m; j++)
{
if(grid[i][j]=='+')
{
if(grid[i][j+1]=='+' && grid[i][j-1]=='+' && grid[i-1][j] =='+' && grid[i+1][j]=='+'){
v.pb({i,j});
}
}
}
}
if(v.size()==0){
cout<<1<<endl;
return;
}
ll mx = -1, pmx = (min(n,m) * 2)-1;
for(auto &p:v)
{
ll f = p.first, s = p.second;
ll c = 0;
ll x = 1;
while(grid[f+x][s]=='+'&& grid[f-x][s]=='+'&& grid[f][s+x]=='+'&&grid[f][s-x]=='+' && (f+x<=n) && (f-x>=1)&& (s+x<=m)&& (s-x>=1)){
c++; x++;
}
mx = max(mx, (4*c+1));
//cout<<pmx<<" "<<c<<endl;
if(mx == pmx){
cout<<mx<<endl;
return;
}
}
cout<<mx<<endl;
}
int main() {
ALLAHU_AKBAR
ll t = 1;
cin>>t;
while(t--)
{
sir();
}
return 0;
}