Teacher Li bought 42 story books and 28 comic books, and distributed 54 books to his classmates. How many books does Teacher Li have?
李老师买来故事书42本，连环画28本，分给同学54本，李老师还有多少本书？
<gadget id="calculator">28 - 54</gadget>
<output>-26</output>

<gadget id="calculator">42 + (-26)</gadget>
<output>16</output>

<result>16</result>