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 5-[(2S)-6-amino-5-ethyl-4-hydroxy-2-methyl-4,5-dihydro-3H-pyridin-2-yl]-2-(3-ethylphenyl)thiophene-3-carboxylic acid .
user
C21H26N2O3S
assistant