Xiaohua participated in the summer camp from July 14th to August 9th. How many days did he participate in?
小华7月14日至8月9日参加了夏令营活动，他一共参加了多少天．
<gadget id="calculator">31 - 14</gadget>
<output>17</output>

<gadget id="calculator">17 + 1 + 9</gadget>
<output>27</output>

<result>27</result>