You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 3-[(2S)-2-(3,4-dihydro-1H-isoquinolin-2-yl)butyl]-1-[(4-methoxyphenyl)methyl]-1-methylurea into its molecular formula.
user
C23H31N3O2
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