#!usr/bin/env python3
from collections import defaultdict,deque
from heapq import heappush, heappop
import sys
import math
import bisect
import random
def LI(): return [int(x) for x in sys.stdin.readline().split()]
def I(): return int(sys.stdin.readline())
def LS():return [list(x) for x in sys.stdin.readline().split()]
def S():
    res = list(sys.stdin.readline())
    if res[-1] == "\n":
        return res[:-1]
    return res
def IR(n):
    return [I() for i in range(n)]
def LIR(n):
    return [LI() for i in range(n)]
def SR(n):
    return [S() for i in range(n)]
def LSR(n):
    return [LS() for i in range(n)]

sys.setrecursionlimit(1000000)
mod = 1000000007

#A
def A():
    a,b = LI()
    for i in range(1,101):
        if a%i == 0 and i%b == 0:
            print("YES")
            return
    print("NO")
    return

#B
def B():
    n,k = LI()
    p = n//(k**2)
    n_ = n-p*k**2
    for k_ in range(100000):
        if k_**2 >= n_:break
    h = p*k+k_
    s = []
    l = 0
    r = k
    for i in range(p):
        for j in range(k):
            s.append(["#" if l <= i < r else "." for i in range(h)])
        l,r = r,r+k
    for j in range(k_):
        s.append(["#" if l <= i < r else "." for i in range(h)])
    su = p*k**2+k_**2
    for i in range(p*k,h)[::-1]:
        if su == n:
            break
        s[-1][i] = "."
        su -= 1
    for i in range(p*k,h-1)[::-1]:
        if su == n:
            break
        s[i][-1] = "."
        su -= 1
    print(h)
    for i in s:
        print(*i,sep = "")
    return

#C
def C():

    return

#D
def D():

    return

#E
def E():

    return

#F
def F():

    return

#Solve
if __name__ == "__main__":
    B()