S=\left[
\begin{array}{cccc}
1 & 3 & 0 & 1
\vspace{0.5em}\\
2 & 0 & 1 & 1
\vspace{0.5em}\\
-2 & -4 & -1 & -2
\vspace{0.5em}\\
-1 & -5 & 0 & -1
\vspace{0.5em}\\
\end{array}
\right]