You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named N-[2-[2-(2-hydroxy-4-nitrophenyl)phenyl]-4-thiophen-3-yl-1,3-oxazol-5-yl]acetamide by IUPAC nomenclature, provide its molecular formula.
user
C21H15N3O5S
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