Let \( f: \mathbb{R} \to \mathbb{R} \) be defined as: \(f(x) = \begin{cases} \frac{a - b \cos 2x}{x^2}, & x < 0, \\ x^2 + cx + 2, & 0 \leq x \leq 1, \\ 2x + 1, & x > 1. \end{cases}\)
If \( f \) is continuous everywhere in \( \mathbb{R} \) and \( m \) is the number of points where \( f \) is NOT differentiable, then \( m + a + b + c \) equals: