The school will be on summer vacation from July 15th, and school will start on September 1st. How many days of vacation have you had in total?
学校从7月15日起放暑假，9月1日开学，-共放了多少天的假？
<gadget id="calculator">31 - 15</gadget>
<output>16</output>

<gadget id="calculator">16 + 1</gadget>
<output>17</output>

<gadget id="calculator">17 + 31</gadget>
<output>48</output>

<result>48</result>