You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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2-[2-[2-[5-[(3,4-dichlorophenyl)methylamino]-7-oxo-6H-pyrazolo[4,3-d]pyrimidin-1-yl]ethoxy]ethoxy]acetic acid is the IUPAC name of a molecule. Please give its molecular formula.
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C18H19Cl2N5O5
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