You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Provide the molecular formula for the IUPAC named substance 5-[4-[(3-fluorophenyl)methylamino]-4-oxobutyl]-N-(4-methylphenyl)-1,3,4-thiadiazole-2-carboxamide .
user
C21H21FN4O2S
assistant