There is a clock, how many times do you strike at what time, and once at half o'clock, from 1 o'clock to 5 o'clock, how many times the clock strikes in total.
有一只钟，几点敲几下，半点敲一下，从1时到5时，这只钟一共敲多少下．
<gadget id="calculator">1 * 4</gadget>
<output>4</output>

<gadget id="calculator">1 + 2 + 3 + 4 + 5 + 4</gadget>
<output>19</output>

<result>19</result>