# Crazy Prime Equation

$\large\dfrac{p}{{p + 1}} + \dfrac{{q + 1}}{q} = \dfrac{{2n}}{{n + 2}}$

Let $$p,q$$ and $$n$$ be positive integers satisfying the equation above, with $$p$$ and $$q$$ are prime numbers. Find the sum of all possible values of $$q-p$$.

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