Use several chess pieces to form a square, and there are 60 pieces in the outermost layer. How many pieces does this square share?
用若干枚棋子摆成一个正方形，最外层共有60枚．这个正方形共用棋子多少枚？
<gadget id="calculator">60 / 4</gadget>
<output>15</output>

<gadget id="calculator">15 + 1</gadget>
<output>16</output>

<gadget id="calculator">16 * 16</gadget>
<output>256</output>

<result>256</result>