digraph G{
    ordering=out;
    {rank=same;"1";"2"};
    "1"->"2";
    {rank=same;"4";"5"};
    "4"->"5";
    "7"->"5";
    "7"->"4";
    "6"->"1";
    "3"->"6";
    "6"->"4";
    "3"->"8";
}