You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Can you give the molecular formula of the molecule 4-[butyl-[5-(4-fluorophenyl)-1H-pyrazolo[4,3-d]pyrimidin-7-yl]amino]-2-chlorophenol;hydrochloride ?
user
C21H20Cl2FN5O
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