You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
N-(6-azaspiro[2.5]octan-2-yl)-1-methyl-6-oxo-N-(thiophen-3-ylmethyl)pyridine-3-carboxamide The above is the IUPAC name of a molecule. Write its molecular formula.
user
C19H23N3O2S
assistant