You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (2R)-2-acetamido-N-[(2S)-1-amino-3-(1H-indol-3-yl)-1-oxopropan-2-yl]-3-(4-fluorophenyl)propanamide by IUPAC nomenclature, provide its molecular formula.
user
C22H23FN4O3
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