You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Translate the chemical IUPAC name (5S,8S)-N-cyclopropyl-5-(3,4-dichlorophenyl)-8-(methylamino)-5,6,7,8-tetrahydronaphthalene-2-carboxamide into its molecular formula.
user
C21H22Cl2N2O
assistant