Mr. Qin participated in a training activity from February 25th to March 5th, 2012. How many days did this training activity go through?
秦老师在2012年2月25日--3月5日，参加了一次培训活动，这次培训活动经过了多少天．
<gadget id="calculator">29 - 25</gadget>
<output>4</output>

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

<gadget id="calculator">5 + 5</gadget>
<output>10</output>

<result>10</result>