You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-methylsulfonyl-N-[(5-phenyl-1,2,4-oxadiazol-3-yl)methyl]-2,3-dihydroindole-5-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H18N4O4S
assistant