You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[3-(2-aminoethyl)-1H-indol-5-yl]-2-[4-(4-chlorophenyl)piperazin-1-yl]acetic acid is the IUPAC name of a molecule. Please give its molecular formula.
user
C22H25ClN4O2
assistant