A rectangular flower bed is 50 decimeters long and 30 decimeters wide. What is the perimeter of this flower bed?
一个长方形花坛的长是50分米，宽是30分米．这个花坛的周长是多少米？
<gadget id="calculator">50 / 10</gadget>
<output>5</output>

<gadget id="calculator">30 / 10</gadget>
<output>3</output>

<gadget id="calculator">5 + 3</gadget>
<output>8</output>

<gadget id="calculator">8 * 2</gadget>
<output>16</output>

<result>16</result>