You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(4-cyanophenyl)-3-(4-methylpiperidine-1-carbonyl)imidazo[1,5-a]pyridine-1-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C22H21N5O2
assistant