You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (3S,4R)-1-(3-ethylimidazol-4-yl)sulfonyl-4-phenylpyrrolidin-3-amine;hydrochloride by IUPAC nomenclature, provide its molecular formula.
user
C15H21ClN4O2S
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