You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(1R,2S)-N-[1-[(4-chlorophenyl)methyl]pyrazol-3-yl]-2-phenylcyclopropane-1-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H18ClN3O
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