A rectangular flower bed is 15 meters long and 3 meters wide. Xiaojun walked around the flower bed twice. How many meters did he walk in total?
一个长方形花坛的长是15米、宽是3米，小军绕着这个花坛走了2圈，他一共走了多少米？
<gadget id="calculator">15 + 3</gadget>
<output>18</output>

<gadget id="calculator">18 * 2 * 2</gadget>
<output>72</output>

<result>72</result>