There are 36 people in class 31. In the art class, 19 people brought crayons, 25 people brought watercolor pens, and we know that each person brought at least one of these pens. How many people bring both crayons and watercolor pens? people?
三1班有36人，在美术课上，有19人带了蜡笔，25人带了水彩笔，又知道每人至少带了其中的一种笔，求既带蜡笔又带水彩笔的有几人？
<gadget id="calculator">25 - 36</gadget>
<output>-11</output>

<gadget id="calculator">19 + (-11)</gadget>
<output>8</output>

<result>8</result>