You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named (19S)-10,19-diethyl-6-fluoro-19-hydroxy-8-(4-hydroxybutyl)-7-methyl-17-oxa-3,13-diazapentacyclo[11.8.0.02,11.04,9.015,20]henicosa-1(21),2,4,6,8,10,15(20)-heptaene-14,18-dione;phosphanylphosphane by IUPAC nomenclature, provide its molecular formula.
user
C27H33FN2O5P2
assistant