You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
[4-[(7-hydroxy-1-methyl-2,3-dihydro-1H-inden-4-yl)methyl]-3,5-dimethylphenoxy]methylphosphonic acid The above is the IUPAC name of a molecule. Write its molecular formula.
user
C20H25O5P
assistant