# Modular arithmetic and algebra

Algebra Level 5

$\begin{cases} a \equiv 101 \pmod{2017} \\ b \equiv 106 \pmod{2017} \\ c \equiv 672 \pmod{2017} \\ x \equiv r \pmod{2017} \\ x^3+20ax^2-19bx-3c=0 \end{cases}$

Given that $$r$$ ($$0\leq r \leq 2016$$) satisfies the system of equations above, find $$r$$.

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