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