SCC1:(A,B) (B,C)(C,D)(D,A)
SCC2:(G,E)(E,F)(F,G)(E,H)(H,E)
NonScc:(C,E)
Suppose  A  is the base point(choose randomly),  the time of composition is at least 3.
However, if we choose C as the base point , we only need 2 compositions around SCC1.  The similar situation happen to SCC2.
we delete B(composition (A,C)), and then C(composition (A,D);composition (A,E)): —> we have 2 choice
1. continute composition with A as the base point. In this case, we continue to composition (A,H)composition (A,F) composition (A,G) ? Is this the different method to do the composition? The idea is that before we want to delete one vertex in the graph, we have to finish all the composition between the base point and another point that is reachable from  the current vertex to guarantee that we can remove the current vertex safely, namely, we reserve the same resolution (space).
2. move to SCC2 select E as base point to minimize the times of composition…

Which is the one we should select?