Grandpa built a chicken coop with a length of 12 meters and a width of 8 meters against the wall. How many meters is this chicken coop at least?
爷爷靠墙修了一个长12米，宽8米的鸡舍，这个鸡舍至少有多少米？
<gadget id="calculator">8 * 2</gadget>
<output>16</output>

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

<result>28</result>