aaa  ⟪⟫  a
	  ZZZ     aa  a
ZZZ     aa  a
	  ZZZ     bb  a
	  ZZZ     bb  a
aa  a
a

a a a a a a a a a a a a a a a a a a a b a a a
a a a a a a a a a a a a a a a a a a a a b a a
a a a a a a a a a a a a a a a a a a a a a b a