import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int k = sc.nextInt();
        int m = (n + k - 1) / k;
        int mod = n % k;
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < m; i++) {
            char[] arr = new char[m];
            for (int j = 0; j < m; j++) {
                if (((i >= mod) && (i + j) % m < k) || ((i < mod) && (i + j) % m < k - 1)) {
                    arr[j] = '#';
                } else {
                    arr[j] = '.';
                }
            }
            sb.append(arr).append("\n");
        }
        System.out.println(m);
        System.out.print(sb);
    }
}