You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-methyl-N-[(1S)-2,2,2-trichloro-1-[(3-cyano-5,6-dihydro-4H-cyclopenta[b]thiophen-2-yl)amino]ethyl]benzamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H16Cl3N3OS
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