tunnel

turtle.refuel()
turtle.select(2)
for laenge = 1,10,1 do
  turtle.forward()
  turtle.turnLeft()
  for breite = 1,3,1 do
    if(turtle.detectDown()) then
      turtle.digDown()
    end
    turtle.placeDown()

    if(turtle.detect()) then
      turtle.dig()
    end
  end
  for i = 1,2,1 do
    turtle.turnLeft()
  end
  for i = 1,3,1 do
    turtle.forward()
  end
  turtle.turnLeft()
  turtle.forward()
end