You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule N-[(Z)-1-(4-butylphenyl)ethylideneamino]-2-(4-oxo-2-sulfanylidene-1H-pyrimidin-6-yl)acetamide into molecular formula.
user
C18H22N4O2S
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