s, k                  k, s
00: 1   00 -> 01, 10  00: 1  k=0 00 -> 01  00: 1
01: 0   01 -> 11      01: 1      10 -> 11  01: 1
10: 0   10 -> 11      10: 1  k=1 00 -> 10  10: 1
11: 0   11 -> .       11: 2      01 -> 11  11: 1