WallChanger

selectedSlot = 1

function items()
    if turtle.getItemCount(selectedSlot) <= 1 then
        selectedSlot = selectedSlot + 1
        if selectedSlot == 17 then
          selectedSlot = 1
        end
        turtle.select(selectedSlot)
    end
end

turtle.turnRight()
while not turtle.detect() do
  turtle.turnLeft()
  turtle.dig()
  turtle.forward()
  while turtle.digUp() do
    turtle.up()
  end
  while not turtle.detectUp() do
    turtle.up()
  end
  while turtle.down() do
    items()
    turtle.placeUp()
  end
  turtle.turnRight()
  turtle.turnRight()
  turtle.forward()
  turtle.turnLeft()
  turtle.forward()
end