You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule 3-[[5-(3-benzyl-4-oxophthalazin-1-yl)-1,3,4-oxadiazol-2-yl]sulfanyl]propane-1-sulfonamide ?
user
C20H19N5O4S2
assistant