If y=y(x) is the solution of the differential equation, √(1-e^2 x) d y-√(4-y^2) · e^x d x=0 such that y(0)=1, then y(- log_e 2) is equal to

If $\displaystyle y=y(x)$ is the solution of the differential equation, $\displaystyle \sqrt{1-e^{2 x}} d y-\sqrt{4-y^2} \cdot e^x d x=0$ such that $\displaystyle y(0)=1$, then $\displaystyle y\left(-\log _e 2\right)$ is equal to