Let \( f,g : \mathbb{N} - \{1\} \to \mathbb{N} \) be functions defined by \( f(a) = \alpha \), where \( \alpha \) is the maximum of the powers of those primes \( p \) such that \( p^{\alpha} \) divided \( a \), and \( g(a) = a + 1 \), for all \( a \in \mathbb{N} - \{1\} \). Then, the function \( f + g \) is:
