You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(4R,7R)-2,8,8-trimethyl-7-[[(2S)-3-methyl-2-(methylamino)-3-phenylbutanoyl]amino]-4-propan-2-ylnona-2,5-dienoic acid is the IUPAC name of a molecule. Please give its molecular formula.
user
C27H42N2O3
assistant