The young pioneers from a certain school participated in the 2014 summer camp. They set off on July 28 and returned on August 5. How many days will the summer camp be held for?
某校的少先队员参加2014年夏令营活动，他们7月28日出发，8月5日回来．这次夏令营活动举办多少天．
<gadget id="calculator">31 - 28</gadget>
<output>3</output>

<gadget id="calculator">3 + 5 + 1</gadget>
<output>9</output>

<result>9</result>