选民 A B C
1 1 0 0
2 1 1 0
3 0 1 1
4 0 0 1
5 0 1 1
6 0 0 1
7 1 1 0
8 0 1 0
9 0 0 0
10 0 0 0
11 1 0 1
12 0 1 0
13 0 0 1
14 1 0 1
15 1 0 1
16 0 1 1
17 0 0 1
18 1 0 0
19 1 0 1
20 1 1 0