The school will have summer vacation on July 12 this year, and it will start on September 1. How many days are there in total?
学校今年7月12日放暑假，到9月1日开学，共放假多少天．
<gadget id="calculator">31 - 12</gadget>
<output>19</output>

<gadget id="calculator">19 + 1</gadget>
<output>20</output>

<gadget id="calculator">20 + 31</gadget>
<output>51</output>

<result>51</result>