#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <cmath>
#include <stdio.h>
#include <queue>
#include <deque>
#include <cstdio>
#include <set>
#include <map>
#include <bitset>
#include <stack>
#include <cctype>
using namespace std;
string s[1010];
int main() {
	int n, k;
	cin >> n >> k;
	int ans = (n + k * k - 1) / (k * k);
	ans *= k;
	for (int i = 0; i < ans; i++) {
		s[i] = "";
		for (int j = 0; j < ans; j++) {
			s[i] += '.';
		}
	}
	for (int i = 0; i < ans; i++) {
		s[i][i / k * k] = '#';
		s[i / k * k][i] = '#';
	}
	for (int i = 1; i < ans; i++) {
		for (int j = 1; j < ans; j++) {
			if (s[i - 1][j] == '#' && s[i][j - 1] == '#') {
				s[i][j] = '#';
			}
		}
	}
	int co = 0;
	for (int i = 0; i < ans; i++) {
		for (int j = 0; j < ans; j++) {
			if (s[i][j] == '#') {
				co++;
			}
		}
	}
	for (int i = ans - 1; i >= 0; i--) {
		for (int j = 0; j < ans - i; j++) {
			if (s[ans - 1 - j][i + j] == '#') {
				if (co > n) {
					s[ans - 1 - j][i + j] = '.';
					co--;
				}
			}
		}
	}
	for (int i = ans - 2; i >= 0; i--) {
		for (int j = 0; j <= i; j++) {
			if (s[i - j][j] == '#') {
				if (co > n) {
					s[i - j][j] = '.';
					co--;
				}
			}
		}
	}
	int m = -1;
	for (int i = 0; i < ans; i++) {
		for (int j = 0; j < ans; j++) {
			if (s[i][j] == '#') {
				if (m < i) {
					m = i;
				}
				if (m < j) {
					m = j;
				}
			}
		}
	}
	cout << m + 1 << endl;
	for (int i = 0; i <= m; i++) {
		cout << s[i].substr(0, m + 1) << endl;
	}
}