K2 K1  K1  K2
0 00 00  0   0
1 00 01  1   0
2 00 10  2   0
3 00 11  3   0
4 01 00  0   1
5 01 01  1   1
6 01 10  2   1
7 01 11  3   1
8 10 00  0   2
9 10 01  1   2
a 10 10  2   2
b 10 11  3   2
c 11 00  0   3
d 11 01  1   3
e 11 10  2   3
f 11 11  3   3