SIZE = 6 (and 1 <= SIZE <= 9)

123456
 23456
  3456
   456
    56
     6

     6
    56
   456
  3456
 23456
123456

1
21
321
4321
54321
654321

     1
    21
   321
  4321
 54321
654321

0     6
01    6
0 2   6
0  3  6
0   4 6
0    56
0     6