clock only strikes on the hour, 1 at 1 am, 2 at 2 am...12 at 12 noon, 1 at 1 pm, 2 at 2 pm...12 at night Knock 12 times, so how many times does the clock have to be knocked in one day and night?
一个时钟只有在整点时才敲出响声，凌晨1时敲1下，凌晨2时敲2下…中午12时敲12下，下午1时敲1下，下午2时敲2下…夜里12时敲12下，那么一昼夜该时钟共要敲多少下？
<gadget id="calculator">1 + 12</gadget>
<output>13</output>

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

<gadget id="calculator">13 * 6 * 2</gadget>
<output>156</output>

<result>156</result>