You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[(5-bromopyridin-2-yl)methyl]-6,6-dimethyl-3-propan-2-ylpiperazine-2,5-dione is the IUPAC name of a molecule. Please give its molecular formula.
user
C15H20BrN3O2
assistant