Let \(M = \left\{ A = \begin{pmatrix} a & b \\
c & d \end{pmatrix} : a, b, c, d \in \{ \pm 3, \pm 2, \pm 1, 0 \} \right\}\). Define \(f: M \to \mathbb{Z}\) as \(f(A) = \det(A)\), for all \(A \in M\), where \(\mathbb{Z}\) is the set of all integers. Then the number of \(A \in M\) such that \(f(A) = 15\) is equal to __________.