Homomorphisms and Isomorphisms · Easy problem

A homomorphism $\varphi: \mathbb Z_9 \to \mathbb Z_{12}$ is determined by $\varphi(1)$, and $9\varphi(1) \equiv 0$ in $\mathbb Z_{12}$ must hold. How many homomorphisms $\varphi: \mathbb Z_9 \to \mathbb Z_{12}$ are there in total?