You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(2-cyanoethyl)-2-[[5-(4-fluorophenyl)-4-methyl-1,2,4-triazol-3-yl]sulfanyl]-N-phenylacetamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H18FN5OS
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