You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-(6-methylpyridazin-3-yl)-8-[(2-methyl-1,3-thiazol-4-yl)methyl]-1-oxa-4,8-diazaspiro[5.5]undecane;2,2,2-trifluoroacetic acid is the IUPAC name of a molecule. Please give its molecular formula.
user
C20H26F3N5O3S
assistant