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