A := [[ 4, 6, 1, 2, 7, 5, 3,-8],
      [-1,-4,-7, 6, 5, 3, 2, 8],
      [ 5, 1,-3,-4, 2, 6,-7, 8],
      [ 7, 1, 3, 8, 5, 2, 4,-6],
      [ 6, 1, 4, 3, 5, 7, 2,-8],
      [ 2, 5,-7, 4, 3, 6, 1, 8],
      [ 5,-2, 3, 4, 1,-7, 6,-8],
      [ 1, 5, 6,-2, 3,-7,-8, 4]]: