--stonewalls

function place(slot)
  turtle.select(slot)
  if turtle.detect() == true then
    turtle.dig()
    turtle.place()
  else
    turtle.place()
  end
end

function move(dir)
  if dir == "up" then
    if turtle.detectUp() == false then
      turtle.up()
    else
      turtle.turnLeft()
      turtle.forward()
      turtle.turnRight()
      dir = "down"
    end
  else
    if turtle.detectDown() == false then
      turtle.down()
    else
      turtle.turnLeft()
      turtle.forward()
      turtle.turnRight()
      dir = "up"
    end
  end
  return dir
end



args = {...}

slot = 2
placecounter = 0
ccounter = 0
dir = "up"



for i = 1, tonumber(args[1]), 1 do
  place(slot)
  dir = move(dir)
  ccounter = ccounter + 1
  placecounter = placecounter + 1
  if ccounter == 12 then
    ccounter = 0
    turtle.select(1)
    turtle.refuel(1)
  end
  if placecounter > 62 then
    slot = slot + 1
    placecounter = 0
  end
end