local arg = ...
top = false
for i=0,arg do
    if top then
        turtle.digForward()
        turtle.moveForward()
        turtle.turnLeft()
        turtle.digForward()
        turtle.turnRight()
        turtle.turnRight()
        turtle.digForward()
        turtle.digDown()
        turtle.moveDown()
        turtle.digForward()
        turtle.turnLeft()
        turtle.turnLeft()
        turtle.digForward()
        turtle.turnRight()
    else
        turtle.digForward()
        turtle.moveForward()
        turtle.digUp()
        turtle.turnLeft()
        turtle.digForward()
        turtle.turnRight()
        turtle.turnRight()
        turtle.digForward()
        turtle.moveUp()
        turtle.digForward()
        turtle.turnLeft()
        turtle.turnLeft()
        turtle.digForward()
        turtle.turnRight()
    end
    top = not top
end