The Jiangsu Provincial Department of Education announced that the 2015 summer vacation for kindergartens in primary and secondary schools in Jiangsu is July 10, and the next semester will start on September 1. How many days are there in total?
江苏省教育厅公布，2015年江苏中小学幼儿园暑假放假时间为7月10日，下学期9月1日开学，暑假一共多少天．
<gadget id="calculator">31 - 10</gadget>
<output>21</output>

<gadget id="calculator">21 + 1 + 31</gadget>
<output>53</output>

<result>53</result>