You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(2R)-2-[(2R,5S)-6-[(2S,3S,6R)-6-[(3S,7S,9S,10S,12R)-3-[(2R,5R,6S)-5-ethyl-5-hydroxy-6-methyloxan-2-yl]-15-methoxy-3,10,12-trimethyl-4,6,8-trioxadispiro[4.1.57.35]pentadecan-9-yl]-3-hydroxy-4-methyl-5-oxooctan-2-yl]-5-methyloxan-2-yl]butanoic acid is the IUPAC name of a molecule. Please give its molecular formula.
user
C43H74O11
assistant