There are 24 people in the outermost layer of a square, how many people are there in this square?
一个方阵最外层有24人，这个方阵共有多少人．
<gadget id="calculator">24 + 4</gadget>
<output>28</output>

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

<gadget id="calculator">7 * 7</gadget>
<output>49</output>

<result>49</result>