Last winter vacation, we had a holiday from January 17th to February 9th, how many days of vacation did we have in total?
去年寒假，我们从1月17日放假，到2月9日开学，一共放了多少天假．
<gadget id="calculator">31 - 17</gadget>
<output>14</output>

<gadget id="calculator">14 + 1</gadget>
<output>15</output>

<gadget id="calculator">9 + 15</gadget>
<output>24</output>

<result>24</result>