There is a circular lake with a circumference of 3140 meters and a small island with an area of 5000 square meters in the middle of the lake. If white lotus is planted in the lake, 0.02 kg of white lotus can be harvested per square meter of water surface. How many kilograms of white lotus can be collected in total?
有一个周长是3140米的圆形湖，在湖的中间有一个面积是5000平方米的小岛．如果在湖中种上白莲，每平方米水面可以收白莲0.02千克．一共可以收白莲多少千克？
<gadget id="calculator">3_140 / 3.14 / 2</gadget>
<output>500</output>

<gadget id="calculator">500 ** 2</gadget>
<output>250_000</output>

<gadget id="calculator">3.14 * 250_000</gadget>
<output>785_000</output>

<gadget id="calculator">785_000 - 5_000</gadget>
<output>780_000</output>

<gadget id="calculator">780_000 * 0.02</gadget>
<output>15_600</output>

<result>15_600</result>