Answer the following question: Generate a question that has the following answer:  Two-and-a-half millennia  for the following movie plot:  The prologue, spoken by Galadriel, shows the Dark Lord Sauron forging the One Ring which he can use to conquer the lands of Middle-earth through his enslavement of the bearers of the Rings of Power powerful magical rings given to individuals from the races of Elves, Dwarves and Men. A Last Alliance of Elves and Men is formed to counter Sauron and his forces at the foot of Mount Doom, but Sauron himself appears to kill Elendil, the High King of Arnor and Gondor, and Gil-galad, High King of the Noldor. After Elendil falls his son, Isildur, grabs his father's broken sword Narsil, and slashes at Sauron's hand. The stroke cuts off Sauron's fingers, separating him from the Ring and vanquishing his army. However, because Sauron's life is bound in the Ring, he is not completely defeated until the Ring itself is destroyed. Isildur takes the Ring and succumbs to its temptation, refusing to destroy it, but he is later ambushed and killed by orcs and the Ring is lost in the River Anduin, into which Isildur fell.The Ring is found two-and-a-half millennia later, and eventually it comes to the creature Gollum, who takes it underground for five centuries, giving Gollum "unnaturally long life." The Ring leaves him however, and is found by the hobbit Bilbo Baggins, much to the grief of Gollum. Bilbo returns to his home in the Shire with the Ring, and the story jumps forward in time sixty years. At his 111th birthday, Bilbo leaves the Ring to his nephew and adopted heir Frodo Baggins. The Wizard Gandalf soon learns it is the One Ring, and sends him to Bree with Sam, with plans to meet him there after Gandalf goes to Isengard to meet the head of his order, Saruman. Saruman reveals that the Nazgûl, or Ringwraiths, have left Mordor to capture the Ring and kill whoever carries it; having already turned to Sauron's cause, he then imprisons Gandalf atop Orthanc. Gandalf sees Saruman's ultimate plan; he has begun to destroy the forest surrounding Isengard for fuel to forge weapons for an army of large orcs, the Uruk-hai.Frodo and Sam...
Answer:
The One Ring was lost for how many years?