You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
For the molecule named bicyclo[3.1.0]hexa-1(6),2,4-triene;(3-ethynylpyrazolo[1,5-a]pyrimidin-2-yl)-piperazin-1-ylmethanone by IUPAC nomenclature, provide its molecular formula.
user
C19H17N5O
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