You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-(3-cyanophenyl)-N-(2-methoxyphenyl)-6-methyl-2-sulfanylidene-3,4-dihydro-1H-pyrimidine-5-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H18N4O2S
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