You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 2-[3-amino-5-[(2-chlorophenyl)methylsulfanyl]-1,2,4-triazol-4-yl]-N-benzylacetamide by IUPAC nomenclature, provide its molecular formula.
user
C18H18ClN5OS
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