Let $\mathrm{x}=\mathrm{x}(\mathrm{y})$ be the solution of the differential equation $2 \mathrm{ye}^{\mathrm{x} / \mathrm{y}^2} \mathrm{dx}+\left(\mathrm{y}^2-4 \mathrm{xe}^{\mathrm{x} / \mathrm{y}^2}\right) \mathrm{dy}=0$ such that $\mathrm{x}(1)=0$. Then, $x(e)$ is equal to
