The augmentation ideal of $\mathbb{Z}G$

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Let $G$ be a cyclic group of order $p$ and let $IG$ denote the augmentation ideal of the group ring $\mathbb{Z}G$. I need to find $H^1(G,IG)$.
Since $$0 \rightarrow IG \rightarrow \mathbb{Z}G \rightarrow \mathbb{Z} \rightarrow 0$$ Then we get the long exact sequence $$0 \rightarrow H^0(G,IG) \rightarrow H^0(G,\mathbb{Z}G) \rightarrow H^0(G,\mathbb{Z}) \rightarrow H^1(G,IG) \rightarrow 0$$ as $\mathbb{Z}G$ is projective. I'm not sure how to get it using the above sequence. Is there an alternative way?

Thanks for help.