MathNet 2010 — Part 07 Question 5

Let $p(x) = a_n x^n + a_{n-1} x^{n-1} + \ldots + a_0$, where each $a_i$ is either $1$ or $-1$. Let $r$ be a root of $p$. If $|r| \gt \frac{15}{8}$, what is the minimum possible value of $n$?