You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (3Z)-3-[(4-ethoxyphenyl)methylidene]-6,7,8,9-tetrahydro-5H-imidazo[1,2-a]azepin-2-one into its molecular formula.
user
C17H20N2O2
assistant