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 1-(3-chlorophenyl)-3-[(1R,2S)-1-(4-methylpiperazine-1,4-diium-1-yl)-1-phenylpropan-2-yl]urea .
user
C21H29ClN4O+2
assistant