from sys import stdin
##  input functions for me
def ria(sep = ''):
    if sep == '' :
        return list(map(int, input().split())) 
    else: return list(map(int, input().split(sep)))
def rsa(sep = ''):
    if sep == '' :
        return input().split() 
    else: return input().split(sep)
def ri(): return int(input())
def rd(): return float(input())
def rs(): return input()
##

## main ##
N, K = map(int, input().split())
M1 = N  // (K * K)
rest = N - M1 * K * K
M2 = 0
while True:
    if M2 * M2 >= rest: break
    M2 += 1
M = M1 * K + M2
ar = [['.'] * M for i in range(M)]
#print(M1,M2)
for k in range(M1):
    for i in range(K):
        for j in range(K):
            ar[k * K + i][k * K + j] = '#'
for i in range(M2):
    for j in range(M2):
        if rest == 0: break
        ar[M1 * K + i][M1 * K + j] = '#'
        rest -= 1
print(M)
for i in range(M):
    print("".join(ar[i]))