You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-benzyl-N-(4,5,6,7-tetrahydro-3H-benzimidazol-5-yl)-2,8-diazaspiro[4.5]decane-8-carboxamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C23H31N5O
assistant