Unsafe Tunnel

turtle.select(5)
turtle.refuel(64)
turtle.select(1)
local torch=0
while true do
 turtle.dig()
 turtle.select(4)
 while turtle.compare() do
  turtle.dig()
 end
 turtle.forward()
 turtle.digUp()
 turtle.digDown()
 torch = torch + 1
 turtle.select(1)
 if torch > 7 then
  turtle.turnRight()
  turtle.turnRight()
  turtle.down()
  turtle.place()
  turtle.up()
  turtle.turnLeft()
  turtle.turnLeft()
  torch = 0
 end
 if turtle.getItemCount(16)>0 then
  turtle.down()
  turtle.digDown()
  turtle.select(2)
  turtle.placeDown()
  for i=5,16 do
   turtle.select(i)
   turtle.dropDown()
  end
  turtle.select(1)
  turtle.up()
 end
if turtle.getItemCount(1)<1 then
 exit()
end
end