You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 2-[[5-[(4-aminopiperidin-1-yl)methyl]pyrrolo[2,1-f][1,2,4]triazin-4-yl]amino]-4-chlorobenzonitrile by IUPAC nomenclature, provide its molecular formula.
user
C19H20ClN7
assistant