To make the product of 25*50*125*□ have four 0s at the end, how much should be filled in □.
要使25*50*125*□的积的末尾有四个0，在□里应填入一个数字多少．
<gadget id="calculator">156_250_000 / 25 / 50 / 125</gadget>
<output>1_000</output>

<result>1_000</result>