Among all positive integers n less than 2012, how many n are there that make 2n-n**2 divisible by 7?
在小于2012的所有正整数n中，使得2n-n**2能被7整除的n共有多少个．
<gadget id="calculator">95 * 6</gadget>
<output>570</output>

<gadget id="calculator">570 + 6</gadget>
<output>576</output>

<result>576</result>