There are 45 people in class 31, 16 of them subscribed to "Young Pioneers", 21 people subscribed to "Chinese Science", 14 people subscribed to both publications, and how many people did not subscribe to both publications.
三1班有45人，其中16人订了《少先队员》，21人订了《中国科学》，有14人两种刊物都订了，有多少人两种刊物都没有订．
<gadget id="calculator">21 - 14</gadget>
<output>7</output>

<gadget id="calculator">16 + 7</gadget>
<output>23</output>

<gadget id="calculator">45 - 23</gadget>
<output>22</output>

<result>22</result>