my %graph =(
          'F' => ['B','C','E'],
          'A' => ['B','C'],
          'D' => ['B'],
          'C' => ['A','E','F'],
          'E' => ['C','F'],
          'B' => ['A',''E','F']
        );


##</code><code>##

      B->E
      B->F->E
      B->F->C->E
      B->A->C->E
      B->A->C->F->E