You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[(2-chloro-5-fluorophenyl)methyl]-N-[(1-methylimidazol-2-yl)methyl]-6-azaspiro[2.5]octan-2-amine;hydrochloride is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H25Cl2FN4
assistant