The big clock strikes 7 times at 7 o'clock, and it takes 12 seconds to finish. How many seconds does it take to ring 12 times at 12 o'clock?
大钟7时敲响7下，12秒敲完．12时敲响12下，需要多少秒．
<gadget id="calculator">12 - 1</gadget>
<output>11</output>

<gadget id="calculator">7 - 1</gadget>
<output>6</output>

<gadget id="calculator">12 / 6</gadget>
<output>2</output>

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

<result>22</result>