____________________________
|
| |1 |3 |5 |7
|
|
| |2 |4 |6 |8
|________________________________|
__________________________
|
| |1 |3 |5 |7
|
|
| |2 |4 |6 |8
|_______________________________|
_____________...
|
| _1 _4
| _3 _6
| _2 _5
|____________...
.. _______________...
_7 _10
_9 _12
_8 _11
.. _______________...
.. _________________________
_13 _16 _19
_15 _18
_14 _17 _20
.. _________________________|