test

turn = true
items = true
i = 1
turtle.select(1)

function place()
  if not turtle.placeDown() then
    if (i == 16) or (turtle.getItemCount(i+1) == 0) then
      items = false
    else
      i = i + 1
      turtle.select(i)
      turtle.placeDown()
    end
  end
end

turtle.up()
while items do
  for i = 1, 3 do
    for j = 1, 2 do
      place()
      turtle.forward()
    end
    if i ~= 3 then
      if turn then
        turtle.turnRight()
      else
        turtle.turnLeft()
      end
      place()
      turtle.forward()
      if turn then
        turtle.turnRight()
      else
        turtle.turnLeft()
      end
      turn = not turn
    end
  end
  place()
  turtle.up()
  turtle.turnRight()
  turtle.turnRight()
end