You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(5Z)-3-benzyl-5-[[2-(2,6-dimethylmorpholin-4-yl)-9-methyl-4-oxopyrido[1,2-a]pyrimidin-3-yl]methylidene]-2-sulfanylidene-1,3-thiazolidin-4-one is the IUPAC name of a molecule. Please give its molecular formula.
user
C26H26N4O3S2
assistant