A vegetable field surrounded by a fence (one side against the wall) is 9 meters long and 6 meters wide. How many meters is the minimum fence required?
用篱笆围成的一块菜地(一面靠墙)，长9米，宽6米，至少需要篱笆多少米？
<gadget id="calculator">6 * 2</gadget>
<output>12</output>

<gadget id="calculator">9 + 12</gadget>
<output>21</output>

<result>21</result>