Please answer the following question: The Secret of the Iron Door (Russian: translit. Tayna zheleznoy dveri) is a 1970 Soviet children's film directed by Mikhail Yuzovsky after a screenplay by Aleksandr Rejzhevsky loosely based on a story Wizard walked through the city by Yuri Tomin. Produced by Gorky Film Studio. Runtime - 69 min.Cinematography by Vitaly Grishin. Music by Vadim Gamaleya lyrics by Evgeny Agranovich. Artists - Lyudmila Bezsmertnova Aleksander Vagichev. Editing by Yanina Bogolepova. Given a list of categories: company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, what category does the paragraph belong to?
A:
Film