Grandpa Li leaned on a wall and used a fence to surround a vegetable garden with a length of 20 meters and a width of 16 meters. How many meters of fence is needed at least?
李爷爷靠一面墙用篱笆围一个长20米，宽16米的菜园，至少需要篱笆多少米？
<gadget id="calculator">16 * 2</gadget>
<output>32</output>

<gadget id="calculator">32 + 20</gadget>
<output>52</output>

<result>52</result>