@katherinesoda501 https://slopegame3d.com said:

Your first interpretation is correct. At least 2 must be sandwiched between F and R, regardless of which one comes first. I've never seen your second interpretation for such a rule. Stick with the first.

At least 2 are after F AND before R.

OR

At least 2 are after R AND before F.

Okay, that makes sense. Thanks for the answers.