Cut the largest circle out of a square with side length 4 decimeters, what is the remaining area?
在边长4分米的正方形中剪下一个最大的圆，剩下的面积是多少？
<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 4</gadget>
<output>12.56</output>

<gadget id="calculator">16 - 12.56</gadget>
<output>3.44</output>

<result>3.44</result>