There are 52 students in Class 4, and each of them has ordered at least one newspaper. Among them, 38 people subscribed to "China Youth Daily", and 35 people subscribed to "Juvenile Intellectual Development Newspaper". How many students subscribed to both newspapers?
四1班有52名学生，每人至少订了一份报纸．其中有38人订了《中国少年报》，有35人定了《少年智力开发报》，两种报纸都订的同学有多少人．
<gadget id="calculator">38 + 35</gadget>
<output>73</output>

<gadget id="calculator">73 - 52</gadget>
<output>21</output>

<result>21</result>