You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
ethyl (4S)-6-amino-5-cyano-4-[(1S)-cyclohex-3-en-1-yl]-2-methyl-4H-pyran-3-carboxylate The above is the IUPAC name of a molecule. Write its molecular formula.
user
C16H20N2O3
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