Same thing happened to me, except I couldn't solve it without green's rule. Someone in another comment wrote a hint, and that helped me!
Rot13: V guvax V jnf nffhzvat gung gur 7 ehyrf gbtrgure jbhyq sbepr n fvatyr, erny jbeq. Fb jura V fgnegrq frrvat jung V pbhyq qb sbe gur fvk ehyrf V xarj, V hfrq erny jbeqf, juvpu zrnag V jnf (ol nppvqrag) ybbxvat sbe gur evtug guvat!
