-20 0010000100100101
32
0 1 1
1 2 -1
2 3 -1
3 0 1
4 5 -1
5 6 1
6 7 1
7 4 -1
8 9 1
9 10 -1
10 11 1
11 8 1
12 13 -1
13 14 -1
14 15 -1
15 12 1
0 4 1
1 5 1
2 6 -1
3 7 -1
4 8 1
5 9 1
6 10 1
7 11 -1
8 12 1
9 13 -1
10 14 -1
11 15 -1
12 0 1
13 1 -1
14 2 -1
15 3 1
