You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule N-[(7R,7aR)-3-oxo-2-[4-[1-(2-pyrrolidin-1-ylethyl)cyclobutyl]phenyl]-5,6,7,7a-tetrahydro-1H-pyrrolo[1,2-c]imidazol-7-yl]-5-chlorothiophene-2-carboxamide .
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C27H33ClN4O2S
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