A rectangular frame is 9 cm long, and its width is 4 cm shorter than its length. What is the minimum number of cm needed to frame the frame?
一个长方形镜框，长9厘米，宽比长短4厘米，给这个镜框镶上边，最少需要多少厘米．
<gadget id="calculator">9 - 4</gadget>
<output>5</output>

<gadget id="calculator">9 + 5</gadget>
<output>14</output>

<gadget id="calculator">14 * 2</gadget>
<output>28</output>

<result>28</result>