Pasted

turtle.select(1)
turtle.dig()
turtle.forward()
while turtle.compareUp() do
  turtle.dig()
  turtle.digUp()
  turtle.up()
end
turtle.dig()
turtle.turnRight()
turtle.dig()
turtle.forward()
turtle.turnLeft()
while turtle.compareDown() do
  turtle.dig()
  turtle.digDown()
  turtle.down()
end
turtle.dig()