local mfl, mce = math.floor, math.ceil
local n, k = io.read("*n", "*n")
local size = mce(n / k)
while size * size < n do
  size = size + 1
end
print(size)
local tn = n
local offset = 1
for i = 1, size do
  for j = 1, size do
    if (size + j - offset) % size < k then
      if 0 < tn then
        io.write("#")
        tn = tn - 1
      else
        io.write(".")
      end
    else
      io.write(".")
    end
  end
  io.write("\n")
  offset = offset + k
  if size <= offset then offset = offset - size end
end