Consider all possible isomeric ketones including stereoisomers of molecular formula '${\mathrm{C}}_5{\mathrm{H}}_{10}\mathrm{O}$'.  All these isomers are independently reacted with ${\mathrm{LiAlH}}_4$ (NOTE: stereoisomers are also reacted separately) The, total number of ketones that give a racemic product(s) is/are.