#include <bits/stdc++.h>
using namespace std;
char c[1005][1005];
int x[1005],y[1005];
int main() {
	ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
	int n,m;
	cin >> n >> m;
	int l = 0;
	for (int i=1;i<=n;++i) {
		for (int j=1;j<=m;++j) {
			cin >> c[i][j];
			if (c[i][j] == '#') x[++l] = i,y[l] = j;
		}
	}
	int ans = 0;
	for (int i=1;i<=l;++i) {
		c[x[i]][y[i]] = '.';
		int cnt = 0;
		for (int i=1;i<=n;++i) {
			for (int j=1;j<=m;++j) {
				if (c[i][j] == '.') {
					if (c[i + 1][j] != '#' && c[i][j + 1] != '#' && c[i - 1][j] != '#' && c[i][j - 1] != '#'){
						++cnt;
					}
				}
			}
		}
		ans = max(ans,cnt);
		c[x[i]][y[i]] = '#';
	}
	cout << ans;
	return 0;
}

调了必关