30pts求调

#include<iostream>
using namespace std;
int n, m;
int main() {
	cin >> n >> m;
	char map[n+5][m+5]; bool dig[n+5][m+5];
	for (int i = 1; i <= n; i++) for (int j = 1; j <= m; j++) cin >> map[i][j];
	int tmp = 0;
	for (int i = 1; i <= n; i++) for (int j = 1; j <= m; j++) if (map[i][j] == '.') {
		if (map[i+1][j] != '#' && map[i-1][j] != '#' && map[i][j+1] != '#' && map[i][j-1] != '#') tmp++, dig[i][j] = true;
		else dig[i][j] = false;
	}
	int ans = tmp;
	for (int i = 1; i <= n; i++) for (int j = 1; j <= m; j++) if (map[i][j] == '#') {
		map[i][j] = '.';
		int cnt = 0;
		if (map[i+1][j] == '#' && map[i-1][j] == '#' && map[i][j+1] == '#' && map[i][j-1] == '#') cnt++;
		if (map[i-1][j] == '.') if (map[i-2][j] != '#' && map[i-1][j+1] != '#' && map[i-1][j-1] != '#' && !dig[i-1][j]) cnt++;
		if (map[i+1][j] == '.') if (map[i+2][j] != '#' && map[i+1][j+1] != '#' && map[i+1][j-1] != '#' && !dig[i+1][j]) cnt++;
		if (map[i][j-1] == '.') if (map[i][j-2] != '#' && map[i+1][j-1] != '#' && map[i-1][j-1] != '#' && !dig[i][j-1]) cnt++;
		if (map[i][j+1] == '.') if (map[i][j+2] != '#' && map[i+1][j+1] != '#' && map[i-1][j+1] != '#' && !dig[i][j+1]) cnt++;
		if (tmp + cnt > ans) ans = tmp + cnt;
		map[i][j] = '#';
	}
	cout << ans << endl;
	return 0;
}