Aunt Wang wants to surround a chicken farm with a length of 9 meters and a width of 7 meters. If one side is against a wall, how many meters should the fence be at least?
王大妈想围一个长9米，宽7米的养鸡场，如果一面靠墙，至少要篱笆多少米？
<gadget id="calculator">7 * 2</gadget>
<output>14</output>

<gadget id="calculator">14 + 9</gadget>
<output>23</output>

<result>23</result>