import java.io.*;
import java.util.*;


public class Main_yukicoder883 {

	private static Scanner sc;
	private static Printer pr;

	private static void solve() {
		int n = sc.nextInt();
		int k = sc.nextInt();

		int nn = n / (k * k);
		int r = n - nn * (k * k);

		int rr = (int)Math.sqrt(r);
		if (r > rr * rr) {
			rr++;
		}
		
		int m = nn * k + rr;
		
		char[][] a = new char[m][m];
		for (int i = 0; i < m; i++) {
			Arrays.fill(a[i], '.');
		}
		
		for (int i = 0; i < nn; i++) {
			int xx = i * k;
			int yy = i * k;
			for (int j = 0; j < k; j++) {
				for (int jj = 0; jj < k; jj++) {
					a[xx + j][yy + jj] = '#';
				}
			}
		}
		
		int xx = nn * k;
		int yy = nn * k;
		int cnt = 0;
		out:
		for (int j = 0; j < rr; j++) {
			for (int jj = 0; jj < rr; jj++) {
				a[xx + j][yy + jj] = '#';
				cnt++;
				if (cnt >= r) {
					break out;
				}
			}
		}
		
		
		pr.println(m);
		for (int i = 0; i < m; i++) {
			pr.println(a[i]);
		}
	}

	// ---------------------------------------------------
	public static void main(String[] args) {
		sc = new Scanner(System.in);
		pr = new Printer(System.out);
			
		solve();
			
		pr.close();
		sc.close();
	}

	static class Printer extends PrintWriter {
		Printer(OutputStream out) {
			super(out);
		}
	}
}