Students from Class 4 and Class 3 form a square with 8 people on each side and people at all four vertices. How many students are there in total?
四3班同学围成一个正方形，每边8人，四个顶点都有人，一共有多少名同学．
<gadget id="calculator">8 * 4</gadget>
<output>32</output>

<gadget id="calculator">32 - 4</gadget>
<output>28</output>

<result>28</result>