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

#define N 2000007

bool mp[N];

int u[N], d[N], l[N], r[N];

multiset<int, greater<int> > R[N], C[N];

inline void work() {
	int n, m; scanf("%d%d", &n, &m);
	auto p = [&](int x, int y) {return (x - 1) * m + y;};

	for (int i = 1; i <= n; ++i) R[i].clear();
	for (int j = 1; j <= m; ++j) C[j].clear();
	for (int i = 1; i <= n; ++i)
		for (int j = 1; j <= m; ++j) {
			char c = getchar();
			while (c != '.' && c != '#') c = getchar();
			int pos = p(i, j);
			mp[pos] = (c == '#');
			u[pos] = d[pos] = l[pos] = r[pos] = 0;
		}
	for (int i = 1; i <= n; ++i)
		for (int j = 1, pos; j <= m; ++j) 
			if (!mp[pos = p(i, j)]) {
				u[pos] = (i > 1 ? u[p(i - 1, j)] + 1 : 1);
				l[pos] = (j > 1 ? l[p(i, j - 1)] + 1 : 1);
			}
	for (int i = n; i; --i)
		for (int j = m, pos; j; --j) 
			if (!mp[pos = p(i, j)]) {
				d[pos] = (i < n ? d[p(i + 1, j)] + 1 : 1);
				r[pos] = (j < m ? r[p(i, j + 1)] + 1 : 1);
			}
	for (int i = 1, pos; i <= n; ++i) {
		if (!mp[pos = p(i, 1)]) R[i].insert(r[pos]);
		for (int j = 1; j < m; ++j)
			if (mp[p(i, j)] && !mp[pos = p(i, j + 1)]) R[i].insert(r[pos]);
	}
	for (int j = 1, pos; j <= m; ++j) {
		if (!mp[pos = p(1, j)]) C[j].insert(d[pos]);
		for (int i = 1; i < n; ++i)
			if (mp[p(i, j)] && !mp[pos = p(i + 1, j)]) C[j].insert(d[pos]);
	}
	int mx = 0, mxx = 0;
	auto upd = [&](int x) {
		if (mx < x) {mxx = mx; mx = x;}
		else if (mxx < x) mxx = x;
	};
	for (int i = 1; i <= n; ++i) {
		int sz = R[i].size();
		if (sz) upd(*R[i].begin());
		if (sz > 1) upd(*++R[i].begin());
	}
	int ans = mx + mxx;
	mx = mxx = 0;
	for (int j = 1; j <= m; ++j) {
		int sz = C[j].size();
		if (sz) upd(*C[j].begin());
		if (sz > 1) upd(*++C[j].begin());
	}
	ans = max(ans, mx + mxx);
	for (int i = 1; i <= n; ++i)
		for (int j = 1, pos; j <= m; ++j) 
			if (!mp[pos = p(i, j)]) 
                ans = max(ans, u[pos] + d[pos] + l[pos] + r[pos] - 2 - min({u[pos], d[pos], l[pos], r[pos]}));
	for (int i = 1; i <= n; ++i)
		for (int j = 1, pos; j <= m; ++j) {
			if (!mp[pos = p(i, j)]) {
				int lr = l[pos] + r[pos] - 1;
				int ud = u[pos] + d[pos] - 1;
				// cut lr
				R[i].erase(R[i].lower_bound(lr));
				R[i].insert(l[pos] - 1); R[i].insert(r[pos] - 1);
				mx = 0; mxx = 0;
				int sz = R[i].size();
				if (sz) upd(*R[i].begin());
				if (sz > 1) upd(*++R[i].begin());
				sz = C[j].size();
				if (sz) upd(*C[j].begin());
				if (sz > 1) upd(*++C[j].begin());
				ans = max(ans, mx + mxx);
				R[i].erase(R[i].lower_bound(l[pos] - 1));
				R[i].erase(R[i].lower_bound(r[pos] - 1));
				R[i].insert(lr);
				// cut ud
				C[j].erase(C[j].lower_bound(ud));
				C[j].insert(u[pos] - 1); C[j].insert(d[pos] - 1);
				mx = 0; mxx = 0;
				sz = R[i].size();
				if (sz) upd(*R[i].begin());
				if (sz > 1) upd(*++R[i].begin());
				sz = C[j].size();
				if (sz) upd(*C[j].begin());
				if (sz > 1) upd(*++C[j].begin());
				ans = max(ans, mx + mxx);
				C[j].erase(C[j].lower_bound(u[pos] - 1));
				C[j].erase(C[j].lower_bound(d[pos] - 1));
				C[j].insert(ud);
			} else {
				mx = 0; mxx = 0;
				int sz = R[i].size();
				if (sz) upd(*R[i].begin());
				if (sz > 1) upd(*++R[i].begin());
				sz = C[j].size();
				if (sz) upd(*C[j].begin());
				if (sz > 1) upd(*++C[j].begin());
				ans = max(ans, mx + mxx);
			}
		}
	printf("%d\n", ans);
}

int main() {
	int t; scanf("%d", &t);
	for (int i = 1; i <= t; ++i) work();
	return 0;
}