You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
7-(ethoxymethyl)-2-methyl-5-(thiophen-3-ylmethyl)-6,7-dihydro-4H-pyrazolo[4,3-c]pyridine The above is the IUPAC name of a molecule. Write its molecular formula.
user
C15H21N3OS
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