You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N,3,5-trimethyl-N-[2-oxo-2-(4-phenylpiperazin-1-yl)ethyl]-1H-pyrazole-4-sulfonamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C18H25N5O3S
assistant