You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[(2R)-2-[(1S,2R)-2-hydroxycyclohexyl]pyrrolidin-1-yl]-2-(4-methoxyphenyl)-2-methylpropan-1-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H31NO3
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