Count the distinct enolate anions (removal of one alpha proton, drawn as enolate $\mathrm{C}=\mathrm{C}-\mathrm{O}{}^{-}$) that can be derived from the ketone shown, counting E and Z geometrical isomers of an enolate separately. Give the answer as an integer.

The ketone shown is 2-methylpentan-3-one. Deprotonation of the tertiary CH gives one enolate, $\mathrm{CH}{}_3\mathrm{CH}{}_2\mathrm{C}(\mathrm{O}{}^{-})=\mathrm{C}(\mathrm{CH}{}_3){}_2$, which has two identical methyl groups on one carbon and so no E/Z isomerism. Deprotonation of the CH${}_2$ gives $\mathrm{CH}{}_3\mathrm{CH}=\mathrm{C}(\mathrm{O}{}^{-})\mathrm{CH}(\mathrm{CH}{}_3){}_2$, which exists as E and Z isomers. The total is $1+2=3$, confirmed by RDKit enumeration.