Use a fence to surround a parallelogram flowerbed with side lengths of 4 meters and 2 meters respectively. How many meters of fence are needed?
用篱笆围一块边长分别为4米和2米的平行四边形花圃，需要篱笆多少米？
<gadget id="calculator">4 + 2</gadget>
<output>6</output>

<gadget id="calculator">6 * 2</gadget>
<output>12</output>

<result>12</result>