(15, 20)
          ( 5 )

(8, 10)
          (    )

(4, 20)
          (    )

(12, 30)
          (    )

(4, 2)
          (    )

(20, 25)
          (    )

(5, 5)
          (    )

(18, 6)
          (    )

(9, 12)
          (    )

        +[    ]

(18, 3)
          (    )

(10, 5)
          (    )

(30, 25)
          (    )

(12, 4)
          (    )

(8, 4)
          (    )

(30, 36)
          (    )

(10, 15)
          (    )

(4, 6)
          (    )

(15, 10)
          (    )

        +[    ]

(36, 30)
          (    )

(16, 12)
          (    )

(15, 3)
          (    )

(5, 20)
          (    )

(16, 4)
          (    )

(24, 6)
          (    )

(6, 9)
          (    )

(9, 3)
          (    )

(5, 30)
          (    )

        +[    ]

(3, 15)
          (    )

(36, 6)
          (    )

(4, 24)
          (    )

(2, 4)
          (    )

(12, 15)
          (    )

(8, 2)
          (    )

(8, 10)
          (    )

(30, 12)
          (    )

(6, 3)
          (    )

        +[    ]

(4, 10)
          (    )

(24, 30)
          (    )

(20, 25)
          (    )

(18, 3)
          (    )

(9, 12)
          (    )

(6, 18)
          (    )

(6, 2)
          (    )

(12, 16)
          (    )

(6, 9)
          (    )

        +[    ]

  ++[[       ]]

(15, 20)
          ( 5 )
(8, 10)
          ( 2 )
(4, 20)
          ( 4 )
(12, 30)
          ( 6 )
(4, 2)
          ( 2 )
(20, 25)
          ( 5 )
(5, 5)
          ( 5 )
(18, 6)
          ( 6 )
(9, 12)
          ( 3 )
        +[    ]

(18, 3)
          ( 3 )
(10, 5)
          ( 5 )
(30, 25)
          ( 5 )
(12, 4)
          ( 4 )
(8, 4)
          ( 4 )
(30, 36)
          ( 6 )
(10, 15)
          ( 5 )
(4, 6)
          ( 2 )
(15, 10)
          ( 5 )
        +[    ]

(36, 30)
          ( 6 )
(16, 12)
          ( 4 )
(15, 3)
          ( 3 )
(5, 20)
          ( 5 )
(16, 4)
          ( 4 )
(24, 6)
          ( 6 )
(6, 9)
          ( 3 )
(9, 3)
          ( 3 )
(5, 30)
          ( 5 )
        +[    ]

(3, 15)
          ( 3 )
(36, 6)
          ( 6 )
(4, 24)
          ( 4 )
(2, 4)
          ( 2 )
(12, 15)
          ( 3 )
(8, 2)
          ( 2 )
(8, 10)
          ( 2 )
(30, 12)
          ( 6 )
(6, 3)
          ( 3 )
        +[    ]

(4, 10)
          ( 2 )
(24, 30)
          ( 6 )
(20, 25)
          ( 5 )
(18, 3)
          ( 3 )
(9, 12)
          ( 3 )
(6, 18)
          ( 6 )
(6, 2)
          ( 2 )
(12, 16)
          ( 4 )
(6, 9)
          ( 3 )
        +[    ]

  ++[[       ]]