3x3place

local height = tonumber(({...})[1])

local oldD = turtle.placeDown
local oldU = turtle.placeUp
local old = turtle.place

local function sel()
  for i = 1, 16 do
    if turtle.getItemCount(i) > 0 then
      turtle.select(i)
      return
    end
  end
end

function turtle.placeDown()
  sel()
  return oldD()
end

function turtle.placeUp()
  sel()
  return oldU()
end

function turtle.place()
  sel()
  return old()
end


local function up()
  local plcmnt = height - 1

  for i = 1, plcmnt do
    turtle.up()
    turtle.placeDown()
  end
end

local function down(no)
  local plcmnt = no and height or height - 1

  for i = 1, plcmnt do
    turtle.down()
    if not no then
      turtle.placeUp()
    end
  end
end

local last = down
local function ue(index)
  if last == down then
    up(index)
    last = up
  else
    down(index)
    last = down
  end
end

local function ua(o)
  if o ~= 3 then
    turtle.back()
    turtle.place()
  end
end


for o = 1, 3 do
  ue()
  ua(o)
end
turtle.turnRight()
turtle.back()
turtle.place()
turtle.turnRight()

for o = 1, 3 do
  ue()
  ua(o)
end
turtle.turnLeft()
turtle.back()
turtle.place()
turtle.turnLeft()

for o = 1, 3 do
  ue()
  ua(o)
end
turtle.up()
turtle.placeDown()

turtle.back()
down(true)