There are 50 students in Class 51. Many students love to read extracurricular books, 24 people love to read comics, 20 people love to read novels, 12 people neither like comics nor novels, and they love both comics and novels. How many people like to read novels?
五1班有50人，许多同学爱看课外书，爱看漫画的有24人，爱看小说的有20人，既不爱看漫画也不爱看小说的有12人，既爱看漫画又爱看小说的有多少人？
<gadget id="calculator">42 - 38</gadget>
<output>4</output>

<result>4</result>