[ 67(7)7(7)7(7)7(7)7(7)7(7)77(8)(6)
A
[ (6)(8)7(8)7(8)7(8)7(8)7(8)7(8)7(6)6
[ 6 7(7)7(7)7(7)7(7)7(7)7(7)77(8)(6)
B
[ (6)(7)7(7)(6)(7)7(7)(6)(7)7
[ (6)(6)(6)(6)(6)(6)5(5)6(6)(6)
C
[ (7)(7)(7)(7)(7)(7)66(6)(7)(7),(7),(6) 6
...[B]
...[C]
...[B]
( final )
[(6)(7)7(7)(6)(7)7(7)7(8)9-(10)-8
D [(6)(7)7(7)(6)(7)7
(a)7(8)(7)-(6); (6)7(8)(7)-(6)...