You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(5E)-3-[(2S)-butan-2-yl]-5-[[9-methyl-4-oxo-2-[[(2R)-oxolan-2-yl]methylamino]pyrido[1,2-a]pyrimidin-3-yl]methylidene]-2-sulfanylidene-1,3-thiazolidin-4-one The above is the IUPAC name of a molecule. Write its molecular formula.
user
C22H26N4O3S2
assistant