{wildcat, [[0,0,0,2,6,0,7,0,1], [6,8,0,0,7,0,0,9,0], [1,9,0,0,0,4,5,0,0], [8,2,0,1,0,0,0,4,0], [0,0,4,6,0,2,9,0,0], [0,5,0,0,0,3,0,2,8], [0,0,9,3,0,0,0,7,4], [0,4,0,0,5,0,0,3,6], [7,0,3,0,1,8,0,0,0]]}. {diabolical, [[0,2,0,6,0,8,0,0,0], [5,8,0,0,0,9,7,0,0], [0,0,0,0,4,0,0,0,0], [3,7,0,0,0,0,5,0,0], [6,0,0,0,0,0,0,0,4], [0,0,8,0,0,0,0,1,3], [0,0,0,0,2,0,0,0,0], [0,0,9,8,0,0,0,3,6], [0,0,0,3,0,6,0,9,0]]}. {satanic, [[0,0,0,6,0,0,4,0,0], [7,0,0,0,0,3,6,0,0], [0,0,0,0,9,1,0,8,0], [0,0,0,0,0,0,0,0,0], [0,5,0,1,8,0,0,0,3], [0,0,0,3,0,6,0,4,5], [0,4,0,2,0,0,0,6,0], [9,0,3,0,0,0,0,0,0], [0,2,0,0,0,0,1,0,0]]}. {challenge, [[2,0,0,3,0,0,0,0,0], [8,0,4,0,6,2,0,0,3], [0,1,3,8,0,0,2,0,0], [0,0,0,0,2,0,3,9,0], [5,0,7,0,0,0,6,2,1], [0,3,2,0,0,6,0,0,0], [0,2,0,0,0,9,1,4,0], [6,0,1,2,5,0,8,0,9], [0,0,0,0,0,1,0,0,2]]}. {real_challenge, [[0,2,0,0,0,0,0,0,0], [0,0,0,6,0,0,0,0,3], [0,7,4,0,8,0,0,0,0], [0,0,0,0,0,3,0,0,2], [0,8,0,0,4,0,0,1,0], [6,0,0,5,0,0,0,0,0], [0,0,0,0,1,0,7,8,0], [5,0,0,0,0,9,0,0,0], [0,0,0,0,0,0,0,4,0]]}. {extreme, [[4,0,5,0,0,9,1,0,2], [0,6,0,0,2,0,0,5,0], [0,0,0,0,0,0,0,0,0], [0,0,1,0,0,0,0,0,4], [0,3,0,0,5,0,0,8,0], [7,0,0,0,0,0,9,0,0], [0,0,0,0,0,0,0,0,0], [0,7,0,0,6,0,0,3,0], [1,0,4,5,0,0,8,0,6]]}. {more_extreme, [[0,0,5,7,0,0,0,0,4], [0,1,0,0,4,0,0,7,0], [7,0,0,0,0,1,9,0,0], [6,0,0,0,0,8,4,0,0], [0,3,0,0,5,0,0,2,0], [0,0,1,9,0,0,0,0,6], [0,0,3,8,0,0,0,0,9], [0,4,0,0,3,0,0,5,0], [2,0,0,0,0,5,8,0,0]]}. {seventeen, [[0,0,0,7,0,0,0,0,0], [1,0,0,0,0,0,0,0,0], [0,0,0,4,3,0,2,0,0], [0,0,0,0,0,0,0,0,6], [0,0,0,5,0,9,0,0,0], [0,0,0,0,0,0,4,1,8], [0,0,0,0,8,1,0,0,0], [0,0,2,0,0,0,0,5,0], [0,4,0,0,0,0,3,0,0]]}. {excruciating, [[0,0,4,0,0,5,0,0,3], [0,2,0,0,4,0,0,1,0], [6,0,0,7,0,0,9,0,0], [2,0,0,6,0,0,4,0,0], [0,1,0,0,9,0,0,7,0], [0,0,3,0,0,2,0,0,9], [0,0,7,0,0,9,0,0,8], [0,8,0,0,3,0,0,6,0], [3,0,0,1,0,0,5,0,0]]}. {difficult, [[0,0,0,2,0,0,0,6,9], [4,8,0,0,6,0,2,0,0], [0,0,1,0,0,0,0,0,0], [0,0,0,9,4,0,0,3,0], [1,0,0,0,7,0,0,0,2], [0,3,0,0,5,1,0,0,0], [0,0,0,0,0,0,8,0,0], [0,0,6,0,9,0,0,2,7], [5,1,0,0,0,6,0,0,0]]}. {very_difficult, [[0,5,0,0,0,0,0,1,0], [0,3,0,0,0,9,2,5,0], [0,0,0,0,8,0,0,0,4], [6,0,0,0,0,3,0,0,0], [0,0,2,6,0,8,9,0,0], [0,0,0,5,0,0,0,0,7], [1,0,0,0,2,0,0,0,0], [0,7,6,4,0,0,0,8,0], [0,2,0,0,0,0,0,4,0]]}. {climbing_everest, [[8,0,0,0,0,0,0,0,0], [0,0,3,6,0,0,0,0,0], [0,7,0,0,9,0,2,0,0], [0,5,0,0,0,7,0,0,0], [0,0,0,0,4,5,7,0,0], [0,0,0,1,0,0,0,3,0], [0,0,1,0,0,0,0,6,8], [0,0,8,5,0,0,0,1,0], [0,9,0,0,0,0,4,0,0]]}. {absurd, [[7,0,0,0,0,0,1,0,0], [6,0,0,0,4,5,0,8,0], [0,0,0,0,8,7,0,0,0], [8,0,0,0,0,0,5,1,0], [4,0,0,0,0,0,9,0,0], [0,2,3,0,0,0,0,0,6], [0,0,0,6,2,0,0,0,0], [0,0,0,0,0,0,0,9,0], [1,9,0,3,5,0,4,0,0]]}. {hard, [[0,0,5,3,0,0,0,0,0], [8,0,0,0,0,0,0,2,0], [0,7,0,0,1,0,5,0,0], [4,0,0,0,0,5,3,0,0], [0,1,0,0,7,0,0,0,6], [0,0,3,2,0,0,0,8,0], [0,6,0,5,0,0,0,0,9], [0,0,4,0,0,0,0,3,0], [0,0,0,0,0,9,7,0,0]]}. {empty, [[0,0,0,0,0,0,0,0,0], [0,0,0,0,0,0,0,0,0], [0,0,0,0,0,0,0,0,0], [0,0,0,0,0,0,0,0,0], [0,0,0,0,0,0,0,0,0], [0,0,0,0,0,0,0,0,0], [0,0,0,0,0,0,0,0,0], [0,0,0,0,0,0,0,0,0], [0,0,0,0,0,0,0,0,0]]}.