You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 2-[5-methyl-1-(oxan-4-yl)pyrazole-4-carbonyl]-3,4-dihydro-1H-isoquinoline-7-carboxylic acid into its molecular formula.
user
C20H23N3O4
assistant