#    ____             ____       _________
# __|A   |___________|B   |_____|Z        |_______
#
#         ___________       ____           ____
# _______|Z          |_____|A   |_________|B   |__
#
#
0 1 A
2 1 A
0 2 Z
4 2 Z
2 1 B
4 1 B
4 2 A
6 2 A
4 1 Z
8 1 Z
6 2 B
8 2 B
