light

function refuel()
    if turtle.getFuelLevel() < 10 then
        get_item(1)
        turtle.refuel(1)
    end
end

function get_item(start_slot)
    for v=start_slot, 16 do
        turtle.select(v)
        if turtle.getItemCount() > 0 then
            return
        end
    end
    print("ran out of items")
end

for a=1, 15 do
    for i=0, 128 do
        refuel()
        if not turtle.back() then
            turtle.turnLeft()
            turtle.turnLeft()
            turtle.dig()
            turtle.turnLeft()
            turtle.turnLeft()
            turtle.back()
        end
        if i % 11 == 0 then
            get_item(9)
            turtle.place()
        end
    end
    turtle.turnRight()
    turtle.forward()
    turtle.forward()
    turtle.forward()
    turtle.forward()
    turtle.forward()
    turtle.forward()
    turtle.turnLeft()
    for i=0, 128 do
        refuel()
        turtle.dig()
        turtle.forward()
    end
end