tab: |                                                               |
|                                                               |
|                                                               |
|                                                      0 2 2 2 2|
|  0 0 0 0 2 3 3 3 3 0               0 0 0 0 2 3 3 3 3          |
|0                     3 3 3 3 0 3 0                            |


|                                                               |
|                                                               |
|        2 2 2 2                                                |
|  2 2 2         2 2 2 2 2 2 2 2                                |
|3                               3 0 0 0         3 3 3 0 0     0|
|                                        1 1 1 1           3 0  |