You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named propyl 4-(7-ethyl-6,7-dihydro-5H-thiopyrano[2,3-d]pyrimidin-4-yl)piperazine-1-carboxylate by IUPAC nomenclature, provide its molecular formula.
user
C17H26N4O2S
assistant