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