You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (6S,7S)-3-ethyl-N-(3-methoxyphenyl)-6-phenyl-6,7-dihydro-5H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazine-7-carboxamide into its molecular formula.
user
C20H21N5O2S
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