tunnel3x3

local run = 0
term.write("Distance? ")
run = read() / 2
t = 0
function digAll()
  while turtle.detect() do
    turtle.dig()
    sleep(0.5)
  end
end
function digForward()
  digAll()
  turtle.forward()
  turtle.digUp()
  turtle.digDown()
end
function layerA()
  digForward()
  turtle.turnLeft()
  digForward()
  digForward()
  turtle.turnRight()
end
function layerB()
  digForward()
  turtle.turnRight()
  digForward()
  countTorch()
  digForward()
  turtle.turnLeft()
end
function placeTorch()
  turtle.select(16)
  turtle.placeDown()
end
function countTorch()
  if t >= 10 then
    placeTorch()
    t = t - 10
  end
end
for i = 1, run do
  t = t + 2
  layerA()
  layerB()
end