A rope is 25 meters long, 9 meters are cut off the first time, and 12 meters are cut off the second time, how many meters is the rope shorter?
一根绳子长25米，第一次剪去9米，第二次剪去12米，这根绳子短了多少米？
<gadget id="calculator">9 + 12</gadget>
<output>21</output>

<result>21</result>