#include <string>
#include <iostream>
#include <algorithm>
using namespace std;
int N; string s[79], t[79];
int solve() {
	int ret = 0;
	for (int i = 0; i < N; i++) {
		for (int j = -1; j < 2; j++) {
			int res = 0;
			bool f = true;
			if (j != -1) {
				for (int k = 0; k < N - 1; k++) {
					if (s[i][j + k] == '#') f = false;
				}
				res++;
			}
			if (f) {
				for (int k = 0; k < N; k++) t[k] = s[k];
				if(j != -1) for (int k = 0; k < N - 1; k++) t[i][j + k] = '#';
				for (int k = 0; k < N; k++) {
					for (int l = 0; l < 2; l++) {
						bool fa = true;
						for (int m = 0; m < N - 1; m++) {
							if (t[l + m][k] == '#') fa = false;
						}
						if (fa) {
							res++;
							break;
						}
					}
				}
				ret = max(ret, res);
			}
		}
	}
	return ret;
}
int main() {
	cin >> N;
	for (int i = 0; i < N; i++) cin >> s[i];
	int ret = 0; bool fr = true;
	for (int i = 0; i < N; i++) {
		for (int j = 0; j < N; j++) {
			if ((i == 0 || i == N - 1 || j == 0 || j == N - 1) && s[i][j] == '#') fr = false;
		}
	}
	if (fr) ret = 4;
	ret = max(ret, solve());
	for (int i = 0; i < N; i++) t[i] = s[i];
	for (int i = 0; i < N; i++) {
		for (int j = 0; j < N; j++) {
			s[i][j] = t[j][i];
		}
	}
	ret = max(ret, solve());
	cout << ret << endl;
	return 0;
}