You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(E)-2-cyano-N-[4-[(3,4-dimethyl-1,2-oxazol-5-yl)sulfamoyl]phenyl]-3-ethylsulfanyl-3-(methylamino)prop-2-enamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H21N5O4S2
assistant