stairs

stair_slot = 1
stair_max = 4
cobble_slot = 5
cobble_max = 12
    turtle.turnLeft()
    turtle.turnLeft()
    turtle.back()
    turtle.back()
    turtle.down()
    turtle.select(stair_slot)
    turtle.place()
   while turtle.detect()==true do
    turtle.select(cobble_slot)
    turtle.placeDown()
    turtle.back()
    end
 for x=1,1000 do
  repeat
    turtle.placeDown()
    turtle.back()
   until not turtle.placeDown()
    turtle.turnRight()
    turtle.back()
    turtle.back()
    turtle.down()
if turtle.getItemCount(stair_slot) == 0 then
  if stair_slot < stair_max then
    stair_slot = stair_slot+1
  end
end
    turtle.select(stair_slot)
    turtle.place()
if turtle.getItemCount(cobble_slot) == 0 then
  if cobble_slot < cobble_max then
    cobble_slot = cobble_slot+1
  end
end
    turtle.select(cobble_slot)
    turtle.placeDown()
    turtle.back()
    turtle.placeDown()
   end