You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Please write the molecular formula of the molecule (2S)-2-[[(2R)-2-[[(2S)-2-[[(2S)-2-amino-3-hydroxypropanoyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]propanoyl]amino]-4-methylpentanoic acid .
user
C21H32N4O7
assistant