For a square queue, if one horizontal row and one vertical row are reduced, 21 people need to be reduced. Ask how many people there are in the original square queue.
一个正方形队列，如果减少一横行和一竖行，要减少21人，问原正方形队列有多少人．
<gadget id="calculator">21 + 1</gadget>
<output>22</output>

<gadget id="calculator">22 / 2</gadget>
<output>11</output>

<gadget id="calculator">11 * 11</gadget>
<output>121</output>

<result>121</result>