You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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For the molecule named [(3S)-3-(imidazo[1,2-b]pyridazin-6-ylamino)pyrrolidin-1-yl]-[(2S,3R)-2-methyloxolan-3-yl]methanone by IUPAC nomenclature, provide its molecular formula.
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C16H21N5O2
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