#include <iostream>

int calc_m(int n, int k) {
	int l = 0, r = 2000;
	while (r - l > 1) {
		int m = l + (r - l) / 2;
		int v = m < k ? m * m : m * k;
		if (n <= std::min(m, k) * m) r = m;
		else l = m;
	}
	return r;
}

int main() {
	int n, k;
	scanf("%d%d", &n, &k);
	int m = calc_m(n, k);
	char a[m][m + 1];
	for (int i = 0; i < m; i++) {
		for (int j = 0; j < m; j++) {
			if (n && (j + i + m) % m < k) a[i][j] = '#', n--;
			else a[i][j] = '.';
		}
		a[i][m] = '\0';
	}
	printf("%d\n", m);
	for (int i = 0; i < m; i++) puts(a[i]);
	return 0;
}