\begin{bmatrix}
-1 &  0 &  0 &   0 &  1 &  0 &  0 \\
 2 & -1 &  0 &   0 &  0 & -1 &  0 \\
 0 &  1 & -1 &   0 &  0 &  0 &  0 \\
 0 &  0 &  1 &  -1 &  0 &  0 & -1 \\
 0 &  0 &  0 & 3/5 & -1 &  0 &  0 \\
 0 &  1 &  0 &   0 &  1 &  0 &  0 \\
 0 & -1 &  0 &   0 & -1 &  0 &  0 \\
 0 &  0 &  1 &   0 &  0 &  0 &  0
\end{bmatrix}