0	 0 1 0 1 2 1 0 1 0
     1	 0 1 0 2 3 2 0 1 0
     2	 0 1 0 2 3 2 4 5 4
     3	 0 1 2 1 3 1 2 1 0
     4	 0 1 2 1 3 4 2 4 5
     5	 0 1 2 3 4 1 5 3 0
     6	 0 1 2 3 4 3 2 1 0
     7	 0 1 2 3 4 5 0 1 2
     8	 0 1 2 3 4 5 6 7 8