A rectangular photo frame is 20 centimeters long and 15 centimeters wide. If you put lace around it, what is the minimum length of the lace?
一个长方形相框长20厘米，宽15厘米，如果给它四周贴上花边，花边至少长多少厘米．
<gadget id="calculator">20 + 15</gadget>
<output>35</output>

<gadget id="calculator">35 * 2</gadget>
<output>70</output>

<result>70</result>