You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
methyl 2-[(4S)-6-amino-5-cyano-4-(3,4-dimethoxyphenyl)-2,4-dihydropyrano[2,3-c]pyrazol-3-yl]acetate is the IUPAC name of a molecule. Please give its molecular formula.
user
C18H18N4O5
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