question: Who are the parents of the goddess the title of the final novel of the "Percy Jackson & the Olympians" series refers to?
answer: Cronus and Rhea
context: Title: The Titan's Curse
  Passage: The Titan's Curse is a 2007 fantasy-adventure novel based on Greek mythology written by Rick Riordan.  It is the third novel in the "Percy Jackson & the Olympians" series and the sequel to "The Sea of Monsters".  It charts the adventures of the fourteen-year-old demigod Percy Jackson as he and his friends go on a dangerous quest to rescue his friend Annabeth Chase and the Greek goddess Artemis, who have both been kidnapped.
  Title: Hestia
  Passage: In Ancient Greek religion, Hestia ( ; Greek: Ἑστία , "hearth" or "fireside") is a virgin goddess of the hearth, architecture, and the right ordering of domesticity, the family, the home, and the state.  In Greek mythology, she is a daughter of Cronus and Rhea.
  Title: The Demigod Files
  Passage: The Demigod Files is a collection of stories by Rick Riordan published on February 10, 2009.  It is a companion book to series "Percy Jackson & the Olympians".  It contains three short stories, titled "Percy Jackson and the Stolen Chariot", "Percy Jackson and the Bronze Dragon", and "Percy Jackson and the Sword of Hades", as well as a preview of "The Last Olympian".  It is set between the fourth and fifth novels, "The Battle of the Labyrinth" and "The Last Olympian".
  Title: Percy Jackson
  Passage: Perseus "Percy" Jackson is a fictional character, the title character and narrator of Rick Riordan's "Percy Jackson & the Olympians" series.  He is also one of seven main protagonists of the sequel series "The Heroes of Olympus", appearing in every book except "The Lost Hero," and appears in the ongoing "Trials of Apollo" series, making him one of the few characters to appear in all three series of the Camp Half-Blood chronicles.  He has also been a narrator and protagonist in Riordan's Greco-Roman/Egyptian crossover stories, part of the "Demigods and Magicians" collection.  The character serves as the narrator in "Percy Jackson's Greek Gods" and "Percy Jackson's Greek Heroes", also by Rick Riordan.
  Title: The Sea of Monsters
  Passage: The Sea of Monsters is a fantasy-adventure novel based on Greek mythology written by Rick Riordan and published in 2006.  It is the second novel in the "Percy Jackson & the Olympians" series and the sequel to "The Lightning Thief".  This book chronicles the adventures of thirteen-year-old demigod Percy Jackson as he and his friends rescue his satyr friend Grover from the Cyclops Polyphemus and save the camp from a Titan's attack by bringing the Golden Fleece to cure Thalia's poisoned pine tree.
  Title: The Last Olympian
  Passage: The Last Olympian is a fantasy-adventure novel based on Greek mythology by Rick Riordan, published on May 5, 2009.  It is the fifth and final novel of the "Percy Jackson & the Olympians" series and serves as the direct sequel to "The Battle of the Labyrinth".  "The Last Olympian" revolves around the demigod Percy Jackson as he leads his friends in a last stand to protect Mount Olympus.  The title refers to Hestia, the goddess of the hearth, who refers to herself as such in a conversation with Percy on Mount Olympus.
citations: The Last Olympian Hestia