You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
2-[6-(2-aminopyrimidin-5-yl)-8-[[3-(hydroxymethyl)cyclobutyl]amino]-1-oxo-2,7-naphthyridin-2-yl]acetamide is the IUPAC name of a molecule. Please give its molecular formula.
user
C19H21N7O3
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