# Complexity! (4)

**Calculus**Level 3

Let complex numbers \(z_{r}\) be the roots of the polynomial \(\displaystyle \sum_{r=0}^{50} z^r\) and that

\[\displaystyle \left| \sum_{r=1}^{50} {\dfrac{1}{z_{r}-1}} \right| = a^{2}\]

Find \(a\), which is a positive integer.

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