There are 43 people in class 3 and 1, and everyone has subscribed to "Chinese Newspaper" or "Mathematics Newspaper". There are 26 people who subscribe to "Chinese Newspaper", 28 people who subscribe to "Mathematics Newspaper", how many people subscribe to both newspapers.
三1班有43人，每人都订了《语文报》或《数学报》．订《语文报》的有26人，订《数学报》的有28人，两种报都订的有多少人．
<gadget id="calculator">26 - 43</gadget>
<output>-17</output>

<gadget id="calculator">28 + (-17)</gadget>
<output>11</output>

<result>11</result>