You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule (2S)-2-[(1S)-2-[4-(1-carbamimidoylpiperidin-4-yl)phenyl]-1-(2H-tetrazol-5-yl)ethyl]hexanoic acid ?
user
C21H31N7O2
assistant