You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (E)-2-acetamido-3-[3-chloro-5-ethoxy-4-[(2-fluorophenyl)methoxy]phenyl]prop-2-enoic acid by IUPAC nomenclature, provide its molecular formula.
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C20H19ClFNO5
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