Wow incredibly difficult!!! I tried for a while and eventually gave up and checked the rules, and looking back I don't know how you're supposed to infer them from what's given.
Rot13: Bar bs gur svefg vffhrf V unq jnf haqrefgnaqvat jung n oynax pbva zrnag. Gur vafgehpgvbaf fnl gb svyy va gur zvffvat pbvaf, ohg gurl qba'g zragvba oynax pbvaf, fb V jnfa'g fher jurgure gurl jrer fhccbfrq gb or svyyrq va be jvyqpneqf be jung. Nyfb V jnfa'g fher vs V jnf fhccbfrq gb or gnxvat pbvaf sebz gur cvyr ba cntr 2 be jurgure V pbhyq hfr nal pbva V arrqrq. (gur fbyhgvbaf vzcyl gur sbezre) Gur pbccre ehyr vf nyfb dhvgr havaghvgvir gb zr. Qbrf gur pbasvthengvba bs gur pbvaf abg znggre sbe pbccre, bayl juvpu barf rkvfg? Svany avgcvpx: gur ahzoref ba gur fbyhgvbaf cntr ner gur chmmyr ahzore abg gur cntr ahzore, juvpu vf pbashfvat tvira gurl hfr gur fnzr vpba. Vg jbhyq or rnfvre gb syvc sebz fbyhgvbaf gb chmmyr vs gur cntr ahzoref jrer yvfgrq vafgrnq.