You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 1,1,1-trifluoro-2-[(7-fluoro-1H-indol-2-yl)methyl]-4-(4-fluorophenyl)-4-methylpentan-2-ol by IUPAC nomenclature, provide its molecular formula.
user
C21H20F5NO
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