You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
methyl 1-[4-[3-(4-chlorophenyl)-1,2,4-oxadiazol-5-yl]butanoyl]-2,3-dihydroindole-2-carboxylate is the IUPAC name of a molecule. Please give its molecular formula.
user
C22H20ClN3O4
assistant