You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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(5Z)-2-cyclohexylidene-3-methyl-5-(1H-pyrrolo[2,3-b]pyridin-3-ylmethylidene)imidazolidin-4-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H20N4O
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