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