import sys

sys.setrecursionlimit(10**6)
int1 = lambda x: int(x)-1
p2D = lambda x: print(*x, sep="\n")
def II(): return int(sys.stdin.buffer.readline())
def FI(): return float(sys.stdin.buffer.readline())
def MI(): return map(int, sys.stdin.buffer.readline().split())
def MF(): return map(float, sys.stdin.buffer.readline().split())
def MI1(): return map(int1, sys.stdin.buffer.readline().split())
def LI(): return list(map(int, sys.stdin.buffer.readline().split()))
def LI1(): return list(map(int1, sys.stdin.buffer.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def BI(): return sys.stdin.buffer.readline().rstrip()
def SI(): return sys.stdin.buffer.readline().rstrip().decode()
dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
inf = 10**16
# md = 998244353
md = 10**9+7

def ceil_sqrt(x):
    a = round(x**0.5+0.45)-1
    while a**2 < x: a += 1
    return a

n,k=MI()
s=max(ceil_sqrt(n),(n+k-1)//k)
k=min(k,s)

tt=[[0]*s for _ in range(s)]
j=0
for i in range(s):
    for _ in range(k):
        tt[i][j]=1
        j+=1
        if j==s:j=0
        n-=1
        if n==0:break
    if n==0:break

print(s)
for row in tt:
    print("".join("#" if a else "." for a in row))