There is a circular garden with a circumference of 12.56 meters. Now that the radius is widened by 1 meter, how much is it increased from the original area?
有一个周长是12.56米的圆形花园．现在半径加宽1米，比原来的面积增加多少？
<gadget id="calculator">12.56 / 3.14 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 + 1</gadget>
<output>3</output>

<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">3.14 * 9</gadget>
<output>28.26</output>

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

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

<gadget id="calculator">28.26 - 12.56</gadget>
<output>15.7</output>

<result>15.7</result>