rr = raw_input
rri = lambda: int(raw_input())
rrm = lambda: map(int, raw_input().split())

def solve(tot, K):
    q, r = divmod(tot, K)
    N = q + (r > 0)
    ans = [['.'] * N for _ in xrange(N)]
    for r, row in enumerate(ans):
        for c in range(r, r+K):
            c %= N
            ans[r][c] = '#'
    return ans

ans = solve(*rrm())
print len(ans)
for row in ans:
    print "".join(row)