#!/usr/bin/env python3
# from typing import *

import sys
import io
import math
import collections
import decimal
import itertools
import bisect
import heapq


def input():
    return sys.stdin.readline()[:-1]


# sys.setrecursionlimit(1000000)

# _INPUT = """# paste here...
# """
# sys.stdin = io.StringIO(_INPUT)

INF = 10**10


N, K = map(int, input().split())

n = N // (K*K)
k = 0
while n * (K*K) + k*k < N:
    k += 1

M = K*n + k
A = [['.'] * M for _ in range(M)]
for n1 in range(n):
    for i in range(K*n1, K*(n1+1)):
        for j in range(K*n1, K*(n1+1)):
            A[i][j] = '#'
for i in range(K*n, K*n+k):
    for j in range(K*n, K*n+k):
        A[i][j] = '#'

print(M)
for i in range(M):
    print(''.join(A[i]))