You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-amino-3-[4-[4-[(3-nitropyridin-2-yl)amino]phenoxy]phenyl]propanoic acid;dihydrochloride is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H20Cl2N4O5
assistant