You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[(6aS)-3-(dimethylsulfamoyl)-6-oxo-7,8,9,10-tetrahydro-6aH-pyrido[1,2-a]quinoxalin-5-yl]-N-[[(2S)-1,4-dioxan-2-yl]methyl]acetamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H30N4O6S
assistant