You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule 2-[(3R,8S,9aS)-8-[(2-methoxy-4-methylsulfanylbenzoyl)amino]-1,4-dioxo-3,6,7,8,9,9a-hexahydro-2H-pyrido[1,2-a]pyrazin-3-yl]acetic acid ?
user
C19H23N3O6S
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