return [ [ 8, 8, 7, 3 ], [ 7, 5, 6, 3 ], [ 1, 2, 9, 4 ], [ 8, 3, 9, 5 ], 
  [ 7, 4, 6, 2 ], [ 9, 9, 2, 5 ], [ 1, 8, 5, 2 ], [ 1, 1, 4, 7 ], 
  [ 6, 6, 4, 3 ] ];
