A rectangular vegetable field is 8 meters long and 5 meters wide. If one side of the vegetable field is against a wall, how many meters should the fence be at least to surround the vegetable field?
一块长方形菜地，长8米，宽5米．如果菜地一面靠墙，给菜地围上篱笆至少要围多少米？
<gadget id="calculator">5 * 2</gadget>
<output>10</output>

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

<result>18</result>