½
0
7
7
0
0
0
0
7
D
b B
0
J
J
J
J
J
J
J
J
J
J
J
J
J
J
1
J
J
J
u
K
B
b D
3
0
K
0
B b
0
0
2
Å
Å
D
D
B
Q K B
M
0
0
