# Does exponent matter?

Algebra Level pending

Let $$(x_i, y_i)$$ be ordered pair of solutions of the equation $x^y + y^x = x + y$ such that $$x_i \leq y_i; x_i, y_i \in \mathbb{Z}; x_i, y_i \in [0, 1000]$$ Evaluate $\sum_{}^{} x_i + y_i$

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