CHECKER	4	4
[0,0,1,0,0,2]	[1,0,2,0,1,2]	[2,0,3,0,2,2]	[3,0,4,0,3,2]	
[0,2,-1,2,0,4]	[1,2,0,2,1,4]	[2,2,1,2,2,4]	[3,2,2,2,3,4]