3x3 Autocraft

--Crafts a 3x3 "compressing recipe" supplied by a container in front and drops it below
if table.getn(arg) < 1 then print("How many items to craft at once?") amount = tonumber(read()) else amount = tonumber(arg[1]) end
while true do
  for i=1, 3 do
    for j=0, 2 do
      local slot = i+j*4
      turtle.select(slot)
      turtle.suck(math.min(amount,math.max(0,amount-turtle.getItemCount(slot))))
    end
  end
  turtle.select(16)
  turtle.craft(amount)
  turtle.dropDown()
end