mineshaft

local data = {...}
local tlong = tonumber(data[1])

function fuel()
  if turtle.getFuelLevel() < 20 then
    turtle.select(16)
    turtle.refuel(1)
    turtle.select(1)
  end
end

fuel()
turtle.up()
if tlong > 0 then
  for i = 1,tlong do
    while turtle.dig() do sleep(0.5) end
    fuel()
    turtle.forward()
    turtle.digDown()
  end
end