How many zeros are there at the end of 4*5*6*7*…*355*356?
4*5*6*7*…*355*356的末尾有多少个零．
<gadget id="calculator">6 * 2</gadget>
<output>12</output>

<gadget id="calculator">72 + 12 + 3</gadget>
<output>87</output>

<result>87</result>