You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (4S,4aR,8aR)-4-(2,4-difluoroanilino)-2,3,4,5,6,7,8,8a-octahydro-1H-naphthalen-4a-ol by IUPAC nomenclature, provide its molecular formula.
user
C16H21F2NO
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