A side of a parallelogram is 15 cm long and 5 cm shorter than the adjacent side. What is the perimeter of this parallelogram in centimeters?
一个平行四边形的一条边长15厘米，比邻边少5厘米．这个平行四边形的周长是多少厘米？
<gadget id="calculator">15 + 5</gadget>
<output>20</output>

<gadget id="calculator">20 + 15</gadget>
<output>35</output>

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

<result>70</result>