A book cover is 25 cm long and 18 cm wide, what is its circumference in cm?
一本书封面长是25厘米，宽是18厘米，它的周长是多少厘米．
<gadget id="calculator">25 + 18</gadget>
<output>43</output>

<gadget id="calculator">43 * 2</gadget>
<output>86</output>

<result>86</result>