StripedTowel

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int n = Integer.parseInt(input.nextLine());
        int m = (int) (n * 1.5);
        for (int i = 0; i < m; i++) {
            int x = i;
            while (x < n + i) {
                if (x % 3 == 0) {
                    System.out.print("#");
                } else {
                    System.out.print(".");
                }
                x++;
            }
            System.out.println();
        }

    }
}