drag

while true do
 os.pullEvent("redstone")
  if redstone.getInput("back") == true then
   os.sleep(70)
   turtle.forward()
   turtle.forward()
   turtle.forward()
   turtle.dig()
   turtle.back()
   turtle.back()
   turtle.back()
   turtle.dropUp()
  end

if turtle.getFuelLevel() < 400 then
     print("Low Fuel")
     turtle.suckDown()
     turtle.refuel(64)
  end

if turtle.getFuelLevel() > 400 then
     print("High Fuel")

  end
end