There are 18 buses in the parking lot, and the number of small cars is 4 times that of large buses. After 5 small cars are driven away, there are as many large trucks. How many large trucks are there?
停车场有18辆大客车，小汽车的辆数是大客车的4倍，小汽车开走5辆后就与大货车同样多，大货车有多少辆？
<gadget id="calculator">18 * 4</gadget>
<output>72</output>

<gadget id="calculator">72 - 5</gadget>
<output>67</output>

<result>67</result>