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  |