You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[(3S)-3-[methyl-(3-pyridin-4-yl-1H-pyrrolo[2,3-b]pyridin-5-yl)amino]piperidin-1-yl]prop-2-en-1-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C21H23N5O
assistant