os.loadAPI("disk/util")

function main()
  levelSector(arg[1])
end

function levelSector(size)
  local doAgainFlag = false;
  local turnFlag = "right";
  while doAgainFlag == true; do
    turtle.dig()
    turtle.forward()
    for i=1,size do
      util.doLine(size-1)
      if turnFlag == "right" then
        turtle.turnRight()
        turtle.dig()
        turtle.forward()
        turtle.turnRight()
        turnFlag == "left"
      end
      if turnFlag == "left" then
        turtle.turnLeft()
        turtle.dig()
        turtle.forward()
        turtle.turnLeft()
        turnFlag == "right"
      end
    end
  end
end