#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;

#define pb push_back
#define MOD 1000000007
#define vll vector<ll>
#define endl "\n" 
#define all(v) v.begin(), v.end()
#define mem(a,b) memset(a, b, sizeof(a))
#define co(n) cout << n << endl
#define yes cout << "YES" << endl
#define no cout << "NO" << endl
#define fr(x, n) for (int i = x; i < n; ++i)
#define fraction(x) cout << fixed << setprecision(x)
#define Baba_Yaga ios_base::sync_with_stdio(0); cin.tie(NULL); cout.tie(NULL);
 
const double eps = 1e-9;
const int N = 2e3+12;

ll gcd(ll a,ll b) { return __gcd(a,b); }
ll lcm(ll a,ll b) { return (a*b)/__gcd(a,b); }

int dx[] = {0, 0, +1, -1, +1, +1, -1, -1};
int dy[] = {+1, -1, 0, 0, +1, -1, +1, -1};

ll arr[N][N], l_r[N][N], r_l[N][N], u_d[N][N], d_u[N][N];

void solve()
{
    mem(arr, 0), mem(l_r, 0), mem(r_l, 0), mem(u_d, 0), mem(d_u, 0);
    ll n, m; cin >> n >> m;
    bool yo = true;
    for(int i=1; i<=n; i++)
    {
        for(int j=1; j<=m; j++)
        {
            char c; cin >> c;
            if(c == '+')
            {
                arr[i][j] = 1;
                yo = false;
            }
            else arr[i][j] = 0;
        }
    }
    // arr input done
    if(yo)
    {
        cout << 0 << endl;
        return;
    }

    for(int i=1; i <= n; i++)
    {
        for(int j=1; j<=m; j++)
        {
            if(arr[i][j] == 0)
            {
                l_r[i][j] = 0;
            }
            else if(arr[i][j] == 1)
            {
                l_r[i][j] = 1 + l_r[i][j-1];
            }
        }
    }

    for(int i=1; i<=n; i++)
    {
        for(int j=m; j>=1; j--)
        {
            if(arr[i][j] == 0)
            {
                r_l[i][j] = 0;
            }
            else if(arr[i][j] == 1)
            {
                r_l[i][j] = 1 + r_l[i][j+1];
            }
        }
    }

    for(int i=1; i<=m; i++)
    {
        for(int j=1; j<=n; j++)
        {
            if(arr[j][i] == 0)
            {
                u_d[j][i] = 0;
            }
            else
            {
                u_d[j][i] = 1 + u_d[j-1][i];
            }   
        }
    }
    
    for(int i=1; i<=m; i++)
    {
        for(int j=n; j>=1; j--)
        {
            if(arr[j][i] == 0)
            {
                d_u[j][i] = 0;
            }
            else
            {
                d_u[j][i] = 1 + d_u[j+1][i];
            }   
        }
    }

    ll ans = 0;

    for(int i=1; i<=n; i++)
    {
        for(int j=1; j<=m; j++)
        {
            if(arr[i][j] == 1)
            {
                ll a = l_r[i][j-1];
                ll b = r_l[i][j+1];
                ll c = u_d[i-1][j];
                ll d = d_u[i+1][j];
                ll mini = min({a, b, c, d});
                ans = max(ans, mini);
            }
        }
    }
    
    cout << ans * 4 + 1 << endl;
}

// --- Think the problem backwards ---

int main()
{
    Baba_Yaga;
    ll tc = 1; cin >> tc;
    while(tc--) solve();
}