-- アーチ建設

local num = 16

local lnum=0

turtle.select(1)


for k=1,8 do
  for j=0,2*num do
    local nn = 0
    lnum =10000000
    for i = 1,num do
       y = ((num - j)^2) + (i^2) - (num ^ 2)
       y= math.abs(y)
       if y <= lnum then
         lnum = y
         nn = i
       end

    end

    for i = 1,num do
      turtle.up()
      if i == nn then

  			if turtle.getItemCount() == 0 then
  				selectNum = turtle.getSelectedSlot()
  				if selectNum == 16 then
  					selectNum = 0
  				end
  				turtle.select(selectNum+1)
  			end
        turtle.placeDown()
      end
    end
    turtle.forward()
    for i = 1,num do
      turtle.down()
    end

  end

  turtle.turnRight()
  turtle.forward()
  turtle.turnLeft()

  for i = 0,2*num do
    turtle.back()
  end

end