import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        char[][] field = new char[n][];
        boolean[][] horArr = new boolean[3][n];
        for (int i = 0; i < n; i++) {
            field[i] = sc.next().toCharArray();
            int count = 0;
            for (int j = 0; j < n; j++) {
                if (field[i][j] == '#') {
                    count++;
                }
            }
            if (count == 1) {
                if (field[i][0] == '#') {
                    horArr[1][i] = true;
                    horArr[2][i] = true;
                } else if (field[i][n - 1] == '#') {
                    horArr[0][i] = true;
                    horArr[2][i] = true;
                }
            } else if (count == 0) {
                horArr[0][i] = true;
                horArr[1][i] = true;
                horArr[2][i] = true;
            }
        }
        boolean[][] verArr = new boolean[3][n];
        for (int i = 0; i < n; i++) {
            int count = 0;
            for (int j = 0; j < n; j++) {
                if (field[j][i] == '#') {
                    count++;
                }
            }
             if (count == 1) {
                if (field[0][i] == '#') {
                    verArr[1][i] = true;
                    verArr[2][i] = true;
                } else if (field[n - 1][i] == '#') {
                    verArr[0][i] = true;
                    verArr[2][i] = true;
                }
            } else if (count == 0) {
                verArr[0][i] = true;
                verArr[1][i] = true;
                verArr[2][i] = true;
            }
        }
        int left = 0;
        int right = 0;
        int hor = 0;
        int up = 0;
        int down = 0;
        int ver = 0;
        int max = 0;
        for (int i = 0; i <n; i++) {
            if (horArr[0][i]) {
                left++;
            } 
            if (horArr[1][i]) {
                right++;
            }
            if (horArr[2][i]) {
                hor++;
            }
            if (verArr[0][i]) {
                up++;
            } 
            if (verArr[1][i]) {
                down++;
            }
            if (verArr[2][i]) {
                ver++;
            }
        }
        if (verArr[2][n - 1]) {
           left++;
        }
        if (verArr[2][0]) {
           right++;
        }
        if (horArr[2][n - 1]) {
           up++;
        }
        if (horArr[2][0]) {
           down++;
        }
        max = Math.max(max, left);
        max = Math.max(max, right);
        max = Math.max(max, hor);
        max = Math.max(max, up);
        max = Math.max(max, down);
        max = Math.max(max, ver);
        System.out.println(max);
    }
 }