You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-ethyl-2-[(2R)-1-[(3-methoxyphenyl)methyl]-3-oxopiperazin-2-yl]-N-propan-2-ylacetamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H29N3O3
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