Write $2017$ numbers on the blackboard: $-\frac{1008}{1008}, -\frac{1007}{1008}, \ldots, -\frac{1}{1008}, 0, \frac{1}{1008}, \frac{2}{1008}, \ldots, \frac{1007}{1008}, \frac{1008}{1008}$.

One processes some steps as follows: erase two arbitrary numbers $x, y$ on the blackboard and then write the number $x + 7xy + y$. After $2016$ steps, there is only one number left. Find the last number on the blackboard in the form of a simplified fraction \(-\frac{k}{m}\). Please provide the value of \(k + m\).

Let's think step by step and output the final answer within \boxed{}.
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