The summer vacation starts on July 2nd and ends on September 1st. How many days are there in total?
暑假从7月2日开始，到9月1日开学，暑假一共有多少天．
<gadget id="calculator">31 - 2</gadget>
<output>29</output>

<gadget id="calculator">29 + 1</gadget>
<output>30</output>

<gadget id="calculator">30 + 31</gadget>
<output>61</output>

<result>61</result>