You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-methyl-N-[[(2S,5S)-7-(thiophen-2-ylmethyl)-1,10-dioxa-7-azaspiro[4.6]undecan-2-yl]methyl]benzamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C22H28N2O3S
assistant