There are some small actors standing around the square stage, with 8 people on each side (there are people at all four vertices), how many young actors are there in total around the stage.
正方形舞台四周站着一些小演员，每边8人(四个顶点都有人)，舞台四周一共有多少个小演员．
<gadget id="calculator">8 - 1</gadget>
<output>7</output>

<gadget id="calculator">7 * 4</gadget>
<output>28</output>

<result>28</result>