Given
$y=\left(\frac{1}{x}\right)^x$
Rewrite:
$y=x^{-x}$
Taking log:
$\ln y=-x\ln x$
Differentiate:
$\frac{1}{y}\frac{dy}{dx}=-(\ln x+1)$
So,
$\frac{dy}{dx}=-x^{-x}(\ln x+1)$
Now differentiate again:
$\frac{d^2y}{dx^2}=x^{-x}\left[(\ln x+1)^2-\frac{1}{x}\right]$
Now put $x=e$
Since $\ln e=1$
$(\ln x+1)^2=(1+1)^2=4$
So,
$\frac{d^2y}{dx^2}\Big|_{x=e}=e^{-e}\left(4-\frac{1}{e}\right)$
Multiply by $e^e$:
$e^e\left(\frac{d^2y}{dx^2}\right)_{x=e}=4-\frac{1}{e}$