function select(slot)
  turtle.select(slot)
  while turtle.getItemCount(slot) == 0 do
    print("Waiting for items in slot "..slot)
    sleep(2)
  end
end

function buildStoneRing()
  for i1=1,3 do
    for i=1,13 do
      if i == 6 or i == 8 then
        select(2)
      elseif i == 7 then
        select(3)
      else
        select(1)
      end
      turtle.placeUp()
      if i ~= 13 then
        turtle.forward()
      end
    end
    turtle.turnLeft()
  end

  -- _
  for i=1,12 do
    if i ~= 6 and i ~= 7 and i ~= 8 then
      select(1)
    elseif i == 6 or i == 8 then
      select(2)
    elseif i == 7 then
      select(3)
    end
    turtle.placeUp()
    turtle.forward()
  end
  turtle.turnLeft()
end

function buildUpsideDownStairs()
  for i1=1,3 do
    for i=1,13 do
      select(4)
      turtle.turnLeft()
      turtle.placeUp()
      turtle.turnRight()
      if i~=13 then turtle.forward() end
    end
    turtle.turnLeft()
  end
  for i=1,12 do
    select(4)
    turtle.turnLeft()
    turtle.placeUp()
    turtle.turnRight()
    turtle.forward()
  end
  turtle.turnLeft()
end

function buildNormalStairs()
  for i1=1,3 do
    for i=1,13 do
      select(5)
      turtle.place()
      turtle.turnRight()
      if i~=13 then turtle.forward() turtle.turnLeft() end
    end
    turtle.turnRight()
  end
  for i=1,12 do
    select(5)
    turtle.place()
    turtle.turnRight()
    turtle.forward()
    turtle.turnLeft()
  end
  turtle.turnRight()
end

--buildStoneRing()
--turtle.down()
--buildUpsideDownStairs()
turtle.down()
turtle.turnLeft()
turtle.back()
buildNormalStairs()