A kind of aquatic plant called water lily grows very fast, doubling every day. In 2012, it just covered the pond, and in a few days it just covered half of the pond area.
一种叫水浮莲的水草生长很快，每天增加1倍，2012天刚好长满池塘，到多少天刚好长满池塘面积的一半．
<gadget id="calculator">2_012 - 1</gadget>
<output>2_011</output>

<result>2_011</result>