function buildRing()
  --  |
  for i=1,13 do
    turtle.placeUp()
    turtle.forward()
  end
  turtle.backward()
  turtle.turnLeft()

  -- -
  for i=1,13 do
    turtle.placeUp()
    turtle.forward()
  end
  turtle.backward()
  turtle.turnLeft()

  -- |
  for i=1,13 do
    turtle.placeUp()
    turtle.forward()
  end
  turtle.backward()
  turtle.turnLeft()

  -- _
  for i=1,13 do
    turtle.placeUp()
    turtle.forward()
  end
  turtle.backward()
  turtle.turnLeft()
end

buildRing()