You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[3-(2-chloroethyl)-4-hydroxyphenyl]-3-[5-(2-fluorophenyl)furan-2-yl]prop-2-en-1-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C21H16ClFO3
assistant