}  \begin{document}  \begin{tikzpicture}  \begin{axis}[counter_barchart]   \addplot coordinates {(0,Ass. Optimization)(00000,with Optimization) (0000,without Optimization)};   \addplot coordinates {(0000,Ass. Optimization) (0000,with Optimization) (0000,without Optimization)};   \legend{Second,First}  \end{axis} \end{tikzpicture} 