The 52 people in the three-year class all signed up for the sports team, of which 37 people joined the basketball team, and 26 people joined the roller skating team. How many people participated in both teams?
三年一班52人都报名参加了体育小组，其中37人参加篮球小组，26人参加轮滑小组，两个小组都参加的有多少人？
<gadget id="calculator">26 - 52</gadget>
<output>-26</output>

<gadget id="calculator">37 + (-26)</gadget>
<output>11</output>

<result>11</result>