1------------------------------------------------------------------
2-----1-1-1-1-1---o-o----------------------------------------------
3--o-------------------2-0-2-0-------------------------------------
4-------------------------------3-3--2-0-------3-2-0---------------
5-----------------------------------------3-----------3------------
6------------------------------------------------------------------
1------------------------------------------------------------------
2-----1-1-1-1-1---o-o----------------------------------------------
3--o-------------------2-0-2-0------------0------------------------
4-------------------------------3-3-3-3-------2-0-2-0--------------
5-----------------------------------------------------3------------
6------------------------------------------------------------------