When Uncle Mustafa, who can't see well, goes to the bank to get his pension, the officer gives a total of 60 banknotes, worth 5 TL and 50 TL, to Uncle Mustafa. Uncle Mustafa, while counting the money he received, mistook the 5 TL banknotes as 50 TL and the 50 TL banknotes as 5 TL and totaled He thinks that 900 TL is overpaid. Accordingly, how many TL is the pension of Uncle Mustafa?​