An organic compound \(P\) having molecular formula \(C_6H_6O_3\) gives ferric chloride test and does not have intramolecular hydrogen bond. The compound \(P\) reacts with 3 equivalents of \(NH_2OH\) to produce oxime \(Q\). Treatment of \(P\) with excess methyl iodide in the presence of KOH produces compound \(R\) as the major product. Reaction of \(R\) with excess iso-butylmagnesium bromide followed by treatment with \(H_3O^+\) gives compound \(S\) as the major product.
The total number of methyl (\(-CH_3\)) group(s) in compound \(S\) is ________.
