I have to calculate a double integral of the function 
\begin{equation\*}
\int\int e^{x+y}dxdy
\end{equation\*}
over the region given by the inequality
\begin{equation\*}
\vert x \vert + \vert y \vert \leq 1.
\end{equation\*}

My question is: what does this region mean? i tried to draw pictures and stuff and tried other things too, but i dont really understand what the region is.

I also have to make use of a change of variables