There are 55 students in Class 3 and 4, everyone subscribes to newspapers, 40 people subscribe to "Youth Daily", and 25 people subscribe to "Little Master Newspaper", so how many people subscribe to the two newspapers.
三4班有学生55人，人人订阅报纸，订《少年报》的有40人，订《小主人报》的有25人，那么多少人订阅两种报纸．
<gadget id="calculator">25 - 55</gadget>
<output>-30</output>

<gadget id="calculator">40 + (-30)</gadget>
<output>10</output>

<result>10</result>