rectangular lawn is 9 meters long and 7 meters wide. Now we need to build a fence around the lawn. If one side is against the wall, how many meters is the minimum required for the fence?
一块长方形的草坪，长9米，宽7米．现在要在草坪的四周围上篱笆，如果一面靠墙，篱笆至少需要多少米？
<gadget id="calculator">9 + 7 + 7</gadget>
<output>23</output>

<result>23</result>