0 0

2 9	+0 +16 +32 +38
0	2	4	6	8	10	12	14	16
1	3	5	7	9	11	13	15	17

1 2
54 0

2 1
1
20

-1 -1

0 7 1
8 15 2
16 23 3
24 31 4
32 39 5
40 47 6
48 55 7