1*2*3*4*5*...*47*48*49*50 How many 0s are there at the end of the product?
1*2*3*4*5*…*47*48*49*50积的末尾有多少个0．
<gadget id="calculator">50 / 5</gadget>
<output>10</output>

<gadget id="calculator">50 / 25</gadget>
<output>2</output>

<gadget id="calculator">10 + 2</gadget>
<output>12</output>

<result>12</result>