# It freaks me out!

Number Theory Level pending

If $$S$$ is the sum of all positive integers satisfying $$x$$ in the equation below:

$x^{2} + (x+1)^{2} + (x+2)^{2}+ \cdots +(x+500)^{2} = (x+501)^{2} + (x+502)^{2} +\cdots + (x+1000)^{2}$

Find $$S \bmod 9$$.

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