Graph Nodes:
X2;X4;X5;X7;X8;X9;X10;X11;X12;X13

Graph Edges:
1. X10 o-> X12
2. X11 o-o X5
3. X11 o-o X7
4. X11 o-o X8
5. X11 o-o X9
6. X13 o-o X11
7. X13 o-o X5
8. X13 o-o X7
9. X13 o-o X8
10. X13 o-o X9
11. X4 o-o X2
12. X5 o-> X12
13. X7 o-o X5
14. X8 o-o X5
15. X8 o-o X7
16. X9 o-> X12
17. X9 o-o X5
18. X9 o-o X7
19. X9 o-o X8

