You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1,4-dimethyl-N-[5-[(4-propan-2-ylsulfonylphenyl)methyl]-1,3,4-oxadiazol-2-yl]pyrazole-3-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H21N5O4S
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