You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-(4-butan-2-ylphenoxy)-N-[(E)-(3-ethoxy-4-hydroxy-5-iodophenyl)methylideneamino]acetamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H25IN2O4
assistant