This is LaTeX code:
[latex]
P=\left[ \begin{array}{ccccc} 1/2 & 1/2 & 0 & 0 &0 \\ 0 & 1/2 & 1/2 & 0 &0 \\ 1/2 & 0 & 0 & 1/2 &0 \\ 0 & 1/2 & 0 & 0 & 1/2 \\ 1/2 & 0 & 0 & 1/2 &0 \end{array} \right]
[/latex]