You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
Can you give the molecular formula of the molecule 6-[(2S)-2-hydroxypropyl]-2-[(3-methylphenyl)methyl]-5,6,7,8-tetrahydro-3H-pyrido[4,3-d]pyrimidin-6-ium-4-one ?
user
C18H24N3O2+
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