You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[(4-bromophenyl)methyl]-2-methyl-3-[[2-(pyrazol-1-ylmethyl)phenyl]methyl]guanidine;hydroiodide is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H23BrIN5
assistant