The clock of the customs building knocks 4 times at 4 o'clock, and it takes 6 seconds to finish the knocking, so how many seconds does it take to knock 8 times at 8 o'clock.
海关大楼时钟4时敲4下，6秒钟敲完，那么8时敲8下，要多少秒敲完．
<gadget id="calculator">8 - 1</gadget>
<output>7</output>

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

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

<gadget id="calculator">7 * 2</gadget>
<output>14</output>

<result>14</result>