The exhibition hall is open from March 10th to March 23rd, how many days in total?
展览馆开放从3月10日至3月23日，共开放多少天
<gadget id="calculator">23 - 10</gadget>
<output>13</output>

<gadget id="calculator">13 + 1</gadget>
<output>14</output>

<result>14</result>