There are some cars in the parking lot. After driving away 27 cars, the rest are arranged in 3 rows with 18 cars in each row. How many cars are parked in the parking lot?
停车场着一些汽车，开走27辆后，剩下的正好排成3行，每行18辆，原来停车场停着多少辆小汽车？
<gadget id="calculator">18 * 3</gadget>
<output>54</output>

<gadget id="calculator">54 + 27</gadget>
<output>81</output>

<result>81</result>