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

b = N//(K*K)
r = N%(K*K)
G = [["." for k in range(1001)] for l in range(1001)]

for p in range(b):
    for x in range(K):
        for y in range(K):
            G[K*p+x][K*p+y] = "#"
if r == 0:
    print(K*b)
    for k in range(K*b):
        print("".join(G[k][:K*b]))
else:
    s = math.ceil(math.sqrt(r))
    c = 0
    for p in range(b,10000000):
        for x in range(s):
            for y in range(s):
                G[K*p+x][K*p+y] = "#"
                c += 1
                if c == r:
                    print(K*b+s)
                    for k in range(K*b+s):
                        print("".join(G[k][:K*b+s]))
                    exit(0)