A 300-meter-long train travels 860 meters per minute when passing through a tunnel. It takes 5 minutes for the train to leave the tunnel from entering the tunnel. How long is this tunnel?
一列车身长300米的火车通过一条隧道时每分钟行860米，火车从进隧道至车尾离开隧道用了5分钟，这条隧道长几千米？
<gadget id="calculator">5 * 860</gadget>
<output>4_300</output>

<gadget id="calculator">4_300 - 300</gadget>
<output>4_000</output>

<gadget id="calculator">4_000 / 1_000</gadget>
<output>4</output>

<result>4</result>