32 Let $\mathbf{R}^{+}$ be the set of all real numbers excluding 0, find all functions $f: \mathbf{R}^{*} \rightarrow \mathbf{R}^{*}$ such that $f(x)+f(y)=f(x y f(x+y))$, where $x$, $y \in \mathbf{R}^{*}$ and $x+y \neq 0$.