Xiao Gu’s vegetable garden is 20 meters long and 12 meters wide. The vegetable garden is surrounded by a bamboo fence. How long is the fence?
小顾家的菜园长20米，宽12米，把这个菜园围上竹篱笆，这个篱笆长多少米？
<gadget id="calculator">20 + 12</gadget>
<output>32</output>

<gadget id="calculator">32 * 2</gadget>
<output>64</output>

<result>64</result>