You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Convert the IUPAC name of a molecule carbanide;3-hydroxy-2-methylbut-2-enoic acid;3-hydroxy-2-methylpropanoic acid;3-hydroxy-2-methylprop-2-enoic acid;2-methylpropanedioic acid;platinum;yttrium into molecular formula.
user
C21H40O13Pt4Y4-4
assistant