The school sent Mr. Li Wei to study in Ganzhou on Children's Day. When he came back on June 15, how many days did Mr. Li Wei study in total?
学校在儿童节这天派李伟老师去赣州学习，6月15日回来，李伟老师一共学习了多少天？
<gadget id="calculator">15 - 1</gadget>
<output>14</output>

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

<result>15</result>