2 B -> 2 C -> 2 3 6 B ~ 6 B ~ 4 A -> 5 B -> 3 C -> j. B -> j. 2 C -> dl. j. C -> 2 C -> 2 3 6 A ~ 6 A ~ 4 A ~ A ~ A -> 6 6 B -> 2 3 6 A ~ 6 A ~ 6 A -> 6 2 3 C