The wall clock strikes 4 times at 4 o'clock and finishes in 6 seconds. Knock 12 times at 12 o'clock, how long does it take to finish knocking?
挂钟4时敲4下，6秒敲完．12时敲12下，敲完需要多长时间？
<gadget id="calculator">12 - 1</gadget>
<output>11</output>

<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">6 / 3</gadget>
<output>2</output>

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

<result>22</result>