from sys import stdin

def main():
    input = lambda: stdin.readline()[:-1]
    N, K = map(int, input().split())

    k = K * K
    n = (N + k - 1) // k
    ans1 = K * n
    ans2 = ['' for _ in [0] * ans1]
    for i in range(ans1):
        s = ''
        col = (i // K) * K
        for j in range(ans1):
            if col <= j < col + K and N > 0:
                s += '#'
                N -= 1
            else:
                s += '.'
            ans2[i] = s
    print(ans1)
    print(*ans2, sep='\n')

main()