Consider the differential equation

$\frac{d^2y(t)}{dt^2}+2\frac{dy(t)}{dt}+y(t)=\delta(t)$ with $y(t)\big|_{t=0^-}=-2$ and $\frac{dy}{dt}\big|_{t=0^-}=0$.

The numerical value of $\frac{dy}{dt}\big|_{t=0^+}$ is