You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-[6-[(2-fluorophenyl)methyl]thieno[2,3-b]pyrrole-5-carbonyl]-2-methyl-N-(2-methylphenyl)piperazine-1-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C27H27FN4O2S
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