Xincheng Primary School wants to make a rectangular flower garden with one side against the wall. The flower garden is 8 meters long and 5 meters wide. How many meters of fence do you need at least?
新城小学想要做一个长方形花圃，一面靠墙，花圃长8米，宽5米，至少需要多少米的篱笆？
<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">8 + 10</gadget>
<output>18</output>

<result>18</result>