A rectangular swimming pool is 50 meters long and 25 meters wide. How many meters is it to walk around the swimming pool for one week?
一个长方形游泳池，长50米，宽25米．沿游泳池走一周是多少米？
<gadget id="calculator">50 + 25</gadget>
<output>75</output>

<gadget id="calculator">75 * 2</gadget>
<output>150</output>

<result>150</result>