platform

left = true
slot = 1

-- Startup prompt
io.write("Hello World.")


-- Checks for Empty slot and switches if empty

local function slotCheck()
  if turtle.getItemCount() == 0 then
    slot = slot + 1
  end
  turtle.select(slot)
end


-- Start of turtle movement

for i = 1, 25 do    -- Set for width

  for j = 1, 9 do   -- Set for depth

    slotCheck()
    turtle.placeDown()
    turtle.forward()

  end

    if left == true then
      turtle.turnLeft()
      turtle.forward()
      turtle.turnLeft()
      turtle.forward()
      left = false
    else
      turtle.turnRight()
      turtle.forward()
      turtle.turnRight()
      turtle.forward()
      left = true

   end

 end