1so
2so
3and
4but
5and
6but
7but
8so
=2
= (2/7-5/7)+(3/11-8/11)
= 1 + (-1)
= 0
A
1 d
2 a
3 b
4 b
5 b
6 d
7 d
8 a
9 a
10 d
1 a
2 a
3 d
4 d
5 c
6 b
7 a
8 d
9 d
10 c
11 a
12 a
13 a
14 c
15 c