{0, 1}  msd_neg_fib

0 1
0 0 -> 0
1 0 -> 1
0 1 -> 2
1 1 -> 3

1 0
0 0 -> 2
1 0 -> 4
0 1 -> 2
1 1 -> 2

2 0
0 0 -> 2
1 0 -> 2
0 1 -> 2
1 1 -> 2

3 1
0 0 -> 0
1 0 -> 1
0 1 -> 2
1 1 -> 2

4 1
0 0 -> 1
1 0 -> 2
0 1 -> 3
1 1 -> 1
