#include <bits/stdc++.h>
#define nl '\n'
#define ll long long int
#define all(v) v.begin(),v.end()
#define print(v) for(auto data : v) cout << data << " "; cout << nl
using namespace std;
const int N = 2e3 + 5;
char mat[N][N];
int n, m;
bool is_valid_i(int i)
{
    return !(i >= n || i < 0);
}
bool is_valid_j(int j)
{
    return !(j >= m || j < 0);
}
void solve()
{
    cin >> n >> m;
    int ans = 0;
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < m; j++)
        {
            cin >> mat[i][j]; mat[i][j] == '+'? ans = 1 : ans;
        }
    }
    if(ans ==  0)
    {
        cout << 0 << nl; return;
    }

    int mx_cnt = min(n,m) + min(n,m) - 1;
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < m; j++)
        {
            if(mat[i][j] == '+')
            {
                int e = i+1, w = i-1, n = j+1, s = j-1;
                int cnt = 0;
                while (is_valid_i(e) && is_valid_i(w) && is_valid_j(n) && is_valid_j(s) &&
                mat[e][j] == '+' && mat[w][j] == '+' && mat[i][n] == '+' && mat[i][s] == '+')
                {
                    cnt += 4; e++, w--, n++, s--;
                }
                ans = max(ans, cnt + 1);
                if(ans == mx_cnt)
                {
                    cout << ans << nl; return;
                }
            }
        }
    }
    cout << ans << nl;
}
int main()
{
    ios_base::sync_with_stdio(false); cin.tie(NULL);

    int t; cin >> t; 
    while (t--) solve();

    return 0;
}