You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
tert-butyl 3-hydroxy-5-oxo-4-[(phenylhydrazinylidene)methyl]-2,6-dihydropyridine-1-carboxylate is the IUPAC name of a molecule. Please give its molecular formula.
user
C17H21N3O4
assistant