In the third grade, 25 people participated in the calligraphy interest group, 19 people participated in the mathematics interest group, and 8 people participated in both interest groups. How many people participated in the interest group?
三年级一共有25人参加书法兴趣小组，有19人参加数学兴趣小组，有8人两种兴趣小组都参加．参加兴趣小组的共有多少人？
<gadget id="calculator">19 - 8</gadget>
<output>11</output>

<gadget id="calculator">25 + 11</gadget>
<output>36</output>

<result>36</result>