There are some female students and 25 male students in the classroom. After leaving 3 male students and 15 female students, there are as many male students as there are female students. It turns out how many female classmates there are.
教室里有一些女同学和25个男同学，走出3个男同学和15个女同学后，剩下的男同学和女同学一样多．原来有女同学多少个．
<gadget id="calculator">25 - 3</gadget>
<output>22</output>

<gadget id="calculator">22 + 15</gadget>
<output>37</output>

<result>37</result>