Our training class starts on July 12th and ends on July 26th. How many days does the training class last?
我们培训班从7月12号开始上课，7月26号结束，培训班上课多少天？
<gadget id="calculator">26 - 12</gadget>
<output>14</output>

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

<result>15</result>