You are given a paragraph, with numbered sentences, and a question. Write the numbers of the sentences needed to answer the given question. Separate multiple sentence numbers with a comma (", "). E.g. "1, 2" would be the correct response if Sent 1 and Sent 2 are needed to answer the given question (do not include sentences that contain no information that is necessary to answer the question). Sort the sentence numbers in an increasing order (i.e., '1, 2', instead of '2, 1'). Your answer should not contain anything than the sentence numbers separated by a comma (e.g. '1, 2, 3, 4'). The given question requires more than one sentence to answer. So, your answer must contain at least one comma (", ").

Paragraph- Sent 1: Durer was born on 21 May 1471, third child and second son of his parents, who had between fourteen and eighteen children.
Sent 2: His father, Albrecht Durer the Elder, was a successful goldsmith, originally Ajtosi, who in 1455 had moved to Nuremberg from Ajtos, near Gyula in Hungary.
Sent 3: The German name "Durer" is a translation from the Hungarian, "Ajtosi".
Sent 4: Initially, it was "Turer," meaning doormaker, which is "ajtos" in Hungarian (from "ajto", meaning door).
Sent 5: A door is featured in the coat-of-arms the family acquired.
Sent 6: Albrecht Durer the Younger later changed "Turer", his father's diction of the family's surname, to "Durer", to adapt to the local Nuremberg dialect.
Sent 7: Albrecht Durer the Elder married Barbara Holper, the daughter of his master, when he himself became a master in 1467.
Sent 8: Durer's godfather was Anton Koberger, who left goldsmithing to become a printer and publisher in the year of Durer's birth and quickly became the most successful publisher in Germany, eventually owning twenty-four printing-presses and having many offices in Germany and abroad.
Sent 9: Koberger's most famous publication was the Nuremberg Chronicle, published in 1493 in German and Latin editions.
Sent 10: It contained an unprecedented 1,809 woodcut illustrations (albeit with many repeated uses of the same block) by the Wolgemut workshop.
Sent 11: Durer may well have worked on some of these, as the work on the project began while he was with Wolgemut.
Sent 12: Because Durer left autobiographical writings and became very famous by his mid-twenties, his life is well documented by several sources.
Sent 13: After a few years of school, Durer started to learn the basics of goldsmithing and drawing from his father.
Sent 14: Though his father wanted him to continue his training as a goldsmith, he showed such a precocious talent in drawing that he started as an apprentice to Michael Wolgemut at the age of fifteen in 1486.
Sent 15: A self-portrait, a drawing in silverpoint, is dated 1484 (Albertina, Vienna) "when I was a child," as his later inscription says.
Sent 16: Wolgemut was the leading artist in Nuremberg at the time, with a large workshop producing a variety of works of art, in particular woodcuts for books.
Sent 17: Nuremberg was then an important and prosperous city, a centre for publishing and many luxury trades.
Sent 18: It had strong links with Italy, especially Venice, a relatively short distance across the Alps. 
Question: Around what year did Durer become famous?.
1, 12.