It takes 26 seconds for a train to pass through a 396-meter bridge, and 18 seconds to pass through a 252-meter tunnel. How many meters is the body length of this train?
一列火车通过396米的大桥需要26秒，通过252米的隧道需要18秒，这列火车车身长是多少米？
<gadget id="calculator">396 - 252</gadget>
<output>144</output>

<gadget id="calculator">26 - 18</gadget>
<output>8</output>

<gadget id="calculator">144 / 8</gadget>
<output>18</output>

<gadget id="calculator">18 * 18</gadget>
<output>324</output>

<gadget id="calculator">324 - 252</gadget>
<output>72</output>

<result>72</result>