There are 17 people in class 31 participating in the mathematics interest group, 13 people participating in the English interest group, and 5 people participating in both interest groups. How many people in class 31 have participated in these two interest groups?
三1班有17人参加数学兴趣小组，13人参加英语兴趣小组，两个兴趣小组都参加了的有5人，三1班共有多少人参加了这两个兴趣小组．
<gadget id="calculator">13 - 5</gadget>
<output>8</output>

<gadget id="calculator">17 + 8</gadget>
<output>25</output>

<result>25</result>