# booklets with at most 0 intersections:

       0        0  a01 b01 c01
       1       13  a02 b02 c02
       2       26  a03 b03 c03

# booklets with at most 1 intersections:

       3        5  a03 b02 c01
       4       15  a01 b03 c02
       5       19  a02 b01 c03

       6        7  a02 b03 c01
       7       11  a03 b01 c02
       8       21  a01 b02 c03

# booklets with at most 2 intersections:

       9        1  a02 b01 c01
      10       14  a03 b02 c02
      11       24  a01 b03 c03

      12        2  a03 b01 c01
      13       12  a01 b02 c02
      14       25  a02 b03 c03

      15        3  a01 b02 c01
      16       16  a02 b03 c02
      17       20  a03 b01 c03

      18        4  a02 b02 c01
      19       17  a03 b03 c02
      20       18  a01 b01 c03

      21        6  a01 b03 c01
      22       10  a02 b01 c02
      23       23  a03 b02 c03

      24        8  a03 b03 c01
      25        9  a01 b01 c02
      26       22  a02 b02 c03

