Mining 3x3 Tunnel

term.clear()
term.setCursorPos(1,1)
print("Dig 3x3 Tunnel forwards")
print("place Turtle in the middle")
print("")
print("Slot 1 for Floor blocks")
print("")
write("Length: ")
s = read()

turtle.select(1)

for i=1, s do
  turtle.dig()
  turtle.forward()
  turtle.digUp()
  turtle.digDown()
  turtle.turnLeft()
  turtle.dig()
  turtle.forward()
  turtle.digUp()
  turtle.digDown()
  turtle.down()
  turtle.placeDown()
  turtle.turnRight()
  turtle.turnRight()
  turtle.forward()
  turtle.placeDown()
  turtle.dig()
  turtle.forward()
  turtle.placeDown()
  turtle.digUp()
  turtle.up()
  turtle.digUp()
  turtle.back()
  turtle.turnLeft()
end