local mfl, mce = math.floor, math.ceil
local n, k = io.read("*n", "*n")
local rep = math.floor(n / (k * k))
local rem = n - rep * k * k
local remsize = math.ceil(math.sqrt(rem))
local size = k * rep + remsize
print(size)
for i = 1, size do
  local bi = mce(i / k)
  for j = 1, size do
    local bj = mce(j / k)
    if bi == bj then
      if 0 < n then
        io.write("#")
        n = n - 1
      else
        io.write(".")
      end
    else
      io.write(".")
    end
  end
  io.write("\n")
end