Let $\left(A^{(m)}\right)_{m \in \mathbb{N}}$ be a sequence in $\mathbf{M}_n$. We assume that for all $m \in \mathbb{N}$, the matrix $A^{(m+1)}$ is similar to $A^{(m)}$, and that this sequence converges to a diagonal matrix $D$.
Finally, show that the diagonal entries of $D$ are the eigenvalues of $A^{(0)}$. What can be said about their multiplicities?