You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule 3,3-dimethyl-N-[(1S)-2-(2-methyl-6-oxo-1H-pyrimidin-4-yl)-1-phenylethyl]butanamide into molecular formula.
user
C19H25N3O2
assistant