During the National Day military parade, there was a solid square formed by Air Force soldiers. There were 156 people on the outermost layer. How many soldiers are there in the square?
国庆节阅兵仪式上，有一队由空军士兵排成的一个中实方阵，最外一层有156人，请问方阵中一共有士兵多少人？
<gadget id="calculator">156 + 4</gadget>
<output>160</output>

<gadget id="calculator">160 / 4</gadget>
<output>40</output>

<gadget id="calculator">40 * 40</gadget>
<output>1_600</output>

<result>1_600</result>