You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named 2-[[4-[(2-amino-4-oxo-3H-pteridin-6-yl)methylamino]benzoyl]-formylamino]pentanedioic acid by IUPAC nomenclature, provide its molecular formula.
user
C20H19N7O7
assistant