21x21
123x123
122x122
x44xx
x33xx
6xx6xx
1xx1xx
2xx2xx
3xx3xx
4xx4xx
5xx5xx
99x9
8x8x8
7x7x7
5x5x5
x1x1x1x
4xx4
x2x2x2x
xxx5xxx
xxx4xxx
xxx6xxx
xxx2xxx
xxx3xxx
xxx1xxx
7xx7
6xx6
8xxx8
5xx5
2xx2
4xxx4
