�� * l� � � Pn Qn / kn S �n Y �n X Io �o = �o �o �o p /p Lp `p xp �p �p 4 �p �p $ q 1q =q Iq + aq # �q �q z �q 8r Fr Sr z gr �r ! s 5 $s $ Zs ; s % �s �s �s &