A rectangular vegetable field with a length of 12 meters and a width of 8 meters, one side is against a wall, and now a fence is required to surround this vegetable field. How long is the minimum length of the fence?
一块长12米，宽8米的长方形菜地，一面靠墙，现在要给这块菜地围上篱笆，篱笆至少长多少米？
<gadget id="calculator">8 * 2</gadget>
<output>16</output>

<gadget id="calculator">12 + 16</gadget>
<output>28</output>

<result>28</result>