Use two identical rectangles (5 cm in length and 3 cm in width) to form a large rectangle. What is the longest perimeter of the assembled large rectangle in cm?
用两个同样的长方形(长是5厘米，宽是3厘米)拼成一个大长方形，拼成的大长方形的周长最长是多少厘米．
<gadget id="calculator">5 + 5 + 3</gadget>
<output>13</output>

<gadget id="calculator">13 * 2</gadget>
<output>26</output>

<result>26</result>