A rectangular vegetable field against a wall is 6 meters long and 3 meters wide. How many meters should the fence be at least to surround the vegetable field?
一面靠墙的长方形菜地，长6米，宽3米．要在菜地的周围围上篱笆，篱笆至少要多少米？
<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">6 + 6</gadget>
<output>12</output>

<result>12</result>