You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-(1,4-diazabicyclo[2.2.2]octan-2-ylmethyl)-1-ethyl-3-(oxolan-2-ylmethyl)guanidine is the IUPAC name of a molecule. Please give its molecular formula.
user
C15H29N5O
assistant