You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-[2-oxo-2-(4,5,6,7-tetrahydro-1,3-benzothiazol-2-ylamino)ethyl]-4-phenylpiperazine-1-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H25N5O2S
assistant