You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-methoxy-5-[(7-methyl-5,6,7,8-tetrahydro-[1]benzothiolo[2,3-d]pyrimidin-4-yl)amino]phenol The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H19N3O2S
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