沒太理解- some good thought but seems you are incorrect
"當 n > 2 and n = 奇數時,N = 2 ( A -> B, B -> A)。"
I have cable ends at A city with A-B-C-D-E-F-G-H-I
I have cable ends at B city with 1-2-3-4-5-6-7-8-9
please explain how your smart moves are to deal with 9 sub-cable condition