local n, k = io.read("*n", "*n")
local rem = n
local sz = 0
while true do
  if rem <= k * k then
    local tmp = math.floor(math.sqrt(rem))
    if tmp * tmp < rem then tmp = tmp + 1 end
    sz = sz + tmp
    break
  else
    rem = rem - k * k
    sz = sz + k
  end
end
print(sz)
local usedline = 0
rem = n
while 0 < rem do
  if k * k <= rem then
    for i = 1, k do
      for j = 1, sz do
        if usedline < j and j <= usedline + k then
          io.write("#")
        else
          io.write(".")
        end
      end
      io.write("\n")
    end
    usedline = usedline + k
    rem = rem - k * k
  else
    local remline = sz - usedline
    for i = 1, remline do
      for j = 1, sz do
        if usedline < j and j <= usedline + remline and 0 < rem then
          io.write("#")
          rem = rem - 1
        else
          io.write(".")
        end
      end
      io.write("\n")
    end
    usedline = sz
  end
end