#include <bits/stdc++.h>
using namespace std;

int32_t main() {
    ios::sync_with_stdio(false);
    cin.tie(0); 
    cout.tie(0);

    #ifdef SUBLIME
        freopen("inputf.in", "r", stdin);
        freopen("outputf.out", "w", stdout);
        freopen("error.txt", "w", stderr);
    #endif

    int tt;
    cin >> tt;
    while (tt--) {
        int n, m;
        cin >> n >> m;
        vector <vector <char>> v(n, vector <char>(m));
        for (auto &x : v) for (auto &y : x) cin >> y;

        int u[n][m], d[n][m], l[n][m], r[n][m];

        for (int i = 0; i < n; i++) {
            l[i][0] = 0;
            for (int j = 1; j < m; j++) {
                if (v[i][j - 1] == '+' && v[i][j] == '+') l[i][j] = l[i][j - 1] + 1;
                else l[i][j] = 0;
            }
        
            r[i][m - 1] = 0;
            for (int j = m - 2; j >= 0; j--) {
                if (v[i][j] == '+' && v[i][j + 1] == '+') r[i][j] = r[i][j + 1] + 1;
                else r[i][j] = 0;
            }
        }

        for (int j = 0; j < m; j++) {
            u[n - 1][j] = 0;
            for (int i = n - 2; i >= 0; i--) {
                if (v[i][j] == '+' && v[i + 1][j] == '+') u[i][j] = u[i + 1][j] + 1;
                else u[i][j] = 0;
            }

            d[0][j] = 0;
            for (int i = 1; i < n; i++) {
                if (v[i][j] == '+' && v[i - 1][j] == '+') d[i][j] = d[i - 1][j] + 1;
                else d[i][j] = 1;
            }
        }

        

        int ans = 0;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                if (v[i][j] == '-') continue;
                ans = max(ans, 1 + 4 * min({u[i][j], d[i][j], l[i][j], r[i][j]}));
            }
        }
        cout << ans << "\n";
    }
    return 0;
}