What time does the wall clock strike? It takes 6 seconds to strike 4 o'clock. How many seconds does it take to strike 12 o'clock?
挂钟几点敲几下，钟敲4点时用了6秒，敲12点时要用多少秒．
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

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

<gadget id="calculator">12 - 1</gadget>
<output>11</output>

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

<result>22</result>