What number season was the Brazillian central defender signed, who was previously a left back?
2012–13 FC Bayern Munich season:  Before the start of the season, Bayern signed Xherdan Shaqiri, Dante, Claudio Pizarro, Mitchell Weiser, Tom Starke and Mario Mandžukić. Dante (footballer): Dante Bonfim Costa Santos (born 18 October 1983), commonly known as Dante (] ), is a Brazilian professional footballer who plays for French Ligue 1 club Nice. Dante (footballer):  Primarily a central defender, he has previously also been used as a defensive midfielder or a left back.
i don't know