You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(5-chloro-3-cyclobutylimidazo[4,5-b]pyridin-2-yl)-3-methoxy-3-methylbutanamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C16H21ClN4O2
assistant