‘\( x \)’ is the product which is obtained from benzene by reacting it with carbon monoxide and hydrogen chloride in the presence of cuprous chloride. ‘\( y \)’ is the major product obtained from the benzene by reacting it with ethanoyl chloride in the presence of anhydrous \( \mathrm{AlCl_3} \). Product (major) obtained by heating \( x \) and \( y \) in the presence of alkali is \( z \). Total number of \( \pi \)(pi) electrons in \( z \) is ______.