1*2*3*...*100, how many consecutive zeros are there at the end of the product of these 100 numbers.
1*2*3*…*100，这100个数乘积的末尾有多少个连续的零．
<gadget id="calculator">100 / 5</gadget>
<output>20</output>

<gadget id="calculator">100 / 25</gadget>
<output>4</output>

<gadget id="calculator">20 + 4</gadget>
<output>24</output>

<result>24</result>