10 \begin{document}

    10 \begin{document}

    11 

    11 

    12 \newcommand{\vertex}{node[circle,fill=black,inner sep=1pt] {}}

    12 \newcommand{\vertex}{node[circle,fill=black,inner sep=1pt] {}}

    13 

    13 

    14 

    14 

    15 \end{document}

    16 \end{document}