Text: The Harem, open from 10:00 a.m. to 4:00 p.m. , can be visited only on the official 30-minute guided tour (offered in English and other languages), for which you must buy an additional ticket.
Entailment: You must take a 30 minuted guided tour if you want to visit the Harem.
Contradiction: The Harem is open 24 hours a day.