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 size = (n + k - 1) / k;
		char[][] field = new char[size][size];
		for (int i = 0; i < size; i++) {
		    Arrays.fill(field[i], '.');
		}
		int count = 0;
		StringBuilder sb = new StringBuilder();
		sb.append(size).append("\n");
		for (int i = 0; i < size; i++) {
		    for (int j = 0; j < size; j++) {
		        if (((j >= i && (i + k - 1) % size >= j) || (i + k > size && (j >= i || (i + k - 1) % size >= j ))) && count < n) {
		            field[i][j] = '#';
		            count++;
		        }
		    }
		    sb.append(new String(field[i])).append("\n");
		}
		System.out.print(sb);
	}
}