What are the invariant factors of $G = (\Bbb Z/12\Bbb Z) \times (\Bbb Z/25 \Bbb Z) \times (\Bbb Z/45\Bbb Z)$?
Writing $\left(\mathbf Z/2\oplus\mathbf Z/4\oplus\mathbf Z/8\right)\oplus\left(\mathbf Z/9\oplus\mathbf Z/27\right)$ in a different way