You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
4-N-cyclobutyl-5-methyl-2-N-(1H-pyrrolo[2,3-b]pyridin-5-yl)pyrimidine-2,4-diamine The above is the IUPAC name of a molecule. Write its molecular formula.
user
C16H18N6
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