If the lengths of two adjacent sides of a parallelogram are 6 cm and 5 cm respectively, what is its perimeter in cm?
一个平行四边形相邻两边的长分别是6厘米和5厘米，它的周长是多少厘米．
<gadget id="calculator">6 + 5</gadget>
<output>11</output>

<gadget id="calculator">11 * 2</gadget>
<output>22</output>

<result>22</result>