1.1 ! root 1: &y � ! 2: � ( �� ! 3: 6 N &� f � j 3 � ! 4: �� � ! 5: �� � ! 6: �� � 0 & &� & & & %& � 6& � G& X& � i& z& � �& � �& & �& & �& �& � �& � �& � � �� ! 7: