You are a chemist. Please follow the instructions to convert the structure to the corresponding name.
system
1-[4-(4-ethoxy-6-methylpyrimidin-2-yl)piperazin-1-yl]-2-(5-fluoro-2-methyl-1H-indol-3-yl)ethanone is the IUPAC name of a molecule. Please give its molecular formula.
user
C22H26FN5O2
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