Similarly, AbcdeF must be Abcde(NOP)(NOP)F, so the output is 2.

Shouldn't that be: Similarly, AbcdeF must be Abcde(NOP)(NOP)(NOP)F, so the output is 3.

Using hyphens instead of (NOP)s:

012345678
Abc-D
A---B---C
Abcde--F
Abcde---F

It may just be a typo. If not, I haven't understood the task.