You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
(3R)-1-[(1R)-1-(4-amino-5,6-dimethylthieno[2,3-d]pyrimidin-2-yl)ethyl]piperidin-3-ol The above is the IUPAC name of a molecule. Write its molecular formula.
user
C15H22N4OS
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