Fortran Example Code for Solving Cyclic Tridiagonal Matrix

I posted a short program which implements the algorithm presented here.

As an example it calculates the following cyclic tridiagonal system $$\begin{bmatrix}  -2 &  1 &  0 &  0 &  2 \\  1 &  -2 &  1 &  0 &  0 \\  0 &  1 &  -2 &  1 &  0 \\  0 &  0 &  1 &  -2 &  1 \\  -1 &  0 &  0 &  1 &  -2 \\ \end{bmatrix} x = \begin{bmatrix}  1 \\  2 \\  3 \\  4 \\  5 \\ \end{bmatrix}.$$