The school sports meeting starts on March 29th and ends on April 1st. How many days does the sports meeting last?
学校运动会从3月29日开始，4月1日结束，运动会开了多少天．
<gadget id="calculator">31 - 29</gadget>
<output>2</output>

<gadget id="calculator">2 + 1</gadget>
<output>3</output>

<result>3</result>