The students are playing games on the playground. Everyone forms a square with 10 people on each side and people at all four vertices. How many people are there in total?
同学们在操场上做游戏．大家围成一个正方形，每边人数都是10人，四个顶点都有人，一共有多少人．
<gadget id="calculator">10 * 4</gadget>
<output>40</output>

<gadget id="calculator">40 - 4</gadget>
<output>36</output>

<result>36</result>