You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-(3,4,6,7,8,8a-hexahydro-1H-pyrrolo[2,1-c][1,4]oxazin-3-ylmethyl)-3-ethyl-2-(2-hydroxy-2-thiophen-2-ylpropyl)guanidine is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H30N4O2S
assistant