You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
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Under IUPAC nomenclature, a molecule named 3-(4-aminopyrazolo[1,5-a][1,3,5]triazin-8-yl)-N-[2-(1H-indol-3-yl)ethyl]propanamide is given. What is its corresponding molecular formula?
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C18H19N7O
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