import sequtils,strutils
var
    N, K : int
(N, K) = stdin.readline.split.map(parseInt)

var
    M = (N + K - 1) div K
    cnt = 0
    ans : array[1005, array[1005, char]]
    l = 0
    r = K - 1
while M * M < N:
    M += 1
echo M

if r >= M:
    r = M - 1
for y in 0..<M:
    for x in 0..<M:
        if cnt == N:
            ans[y][x] = '.'
        elif l <= r and l <= x and x <= r:
            ans[y][x] = '#'
            cnt += 1
        elif l > r and (x >= l or x <= r):
            ans[y][x] = '#'
            cnt += 1
        else:
            ans[y][x] = '.'
    l = (l + 1) mod M
    r = (r + 1) mod M

for y in 0..<M:
    echo ans[y][0..<M].join()