#define _USE_MATH_DEFINES
#include <cstdio>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <complex>
#include <string>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <limits>
#include <climits>
#include <cfloat>
#include <functional>
#include <iterator>
using namespace std;

void rotate(vector<string>& s)
{
    int n = s.size();
    vector<string> t(n, string(n, ' '));
    for(int i=0; i<n; ++i){
        for(int j=0; j<n; ++j){
            t[i][j] = s[j][n-1-i];
        }
    }
    s.swap(t);
}

int solve(vector<string> s)
{
    rotate(s);
    int n = s.size();
    int ans = 0;
    for(int i=0; i<n; ++i){
        if(s[i].substr(0, n-1) == string(n-1, '.') || s[i].substr(1) == string(n-1, '.'))
            ++ ans;
    }
    return ans;
}

int main()
{
    int n;
    cin >> n;
    vector<string> s(n);
    for(int i=0; i<n; ++i)
        cin >> s[i];

    int ans = 0;
    for(int r=0; r<2; ++r){
        for(int k=0; k<9; ++k){
            vector<string> t = s;
            int x = k;
            int cnt = 0;
            for(int i=0; i<2; ++i){
                if(t[i*(n-1)].substr(x%3, n-1) == string(n-1, '.')){
                    t[i*(n-1)].replace(x%3, n-1, n-1, '#');
                    ++ cnt;
                }
                x /= 3;
            }

            cnt += solve(t);
            ans = max(ans, cnt);

        }
        rotate(s);
    }
    cout << ans << endl;

    return 0;
}