Two rectangles with a length of 5 cm and a width of 4 cm are used to form a new rectangle. What is the maximum perimeter of the new rectangle in cm?
用两个长是5厘米，宽是4厘米的长方形拼成一个新长方形，新长方形的周长最大是多少厘米．
<gadget id="calculator">5 + 4</gadget>
<output>9</output>

<gadget id="calculator">9 * 2 * 2</gadget>
<output>36</output>

<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">36 - 8</gadget>
<output>28</output>

<result>28</result>