GRAPH BEGIN a b c b d c d d e GRAPH END a b a c a d a e b c b e GRAPH BEGIN a b c f b d c d d e f g e f GRAPH END a b a c a d a e a f a g b c b d b e b f b g c d c e c f c g d e d f d g e f e g f g GRAPH BEGIN a b c d b e f g c e f g d e f g e h i j f h i j g h i j h k l m i k l m j k l m k n o p l n o p m n o p n q r s o q r s p q r s q t u v r t u v s t u v t w x y u w x y v w x y w z x z y z z y GRAPH END a z b z c z d z e z f z g z h z i z j z k z l z m z n z o z p z q z r z s z t z u z v z w z x z y z z z