You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-tert-butyl-5-methyl-7-[2-(7-methyl-2,7-diazaspiro[3.4]octan-2-yl)propyl]-2,5,7-triazaspiro[3.4]octan-8-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H37N5O
assistant