You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
3-[[3-[2-(benzylamino)ethyl]-2-oxo-1-oxa-3,8-diazaspiro[4.5]decan-8-yl]methyl]-1H-indole-5-carbonitrile is the IUPAC name of a molecule. Please give its molecular formula.
user
C26H29N5O2
assistant