# Problems need HardWork 24

For prime $$x$$, let $$(x_1, y_1), (x_2, y_2), \ldots, (x_n, y_n)$$ be all the integer solutions of $$(x,y)$$ such that they satisfy the equation $$x-y^4=4$$. Find the value of $$\displaystyle \sum_{j=1}^n (x_j+ y_j)$$.

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