You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name 4-butoxy-5-methoxy-9-azatetracyclo[7.5.2.01,10.02,7]hexadeca-2,4,6,13-tetraen-12-one into its molecular formula.
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C20H25NO3
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