Finding 3 abelian groups of order 64

Question

Let $G$ a finit group. We define the exposant of G as the smallest integer $m > 0$ such that $ \forall g \in G : g^m = e$.

Two questions are asked :

1. Show that the exposant of G divide $\vert G \vert$.
2. Find 3 abelian groups non isomorphic of order 64 and exposant 8.

For the first question I showed that the group $<g>$, the group generated by $g$, was a subgroup of $G$ of order $m$. Thus by Lagrange's theorem we know that $m$ divides $\vert G \vert$.