rectangular vegetable field is 8 meters long and 6 meters wide, surrounded by a fence, how long is the fence?
一块长方形菜地，长8米，宽6米，四周围上篱笆，篱笆长多少米米．
<gadget id="calculator">8 + 6</gadget>
<output>14</output>

<gadget id="calculator">14 * 2</gadget>
<output>28</output>

<result>28</result>