Bombykol is a pheromone released by the female silkworm moth to attract mates. It reacts with acetic anhydride to give an ester, which on ozonolysis gives a mixture of butanal, glyoxal and 10-acetoxy decanal. The total number of ${\text{sp}}^{\text{3}}$ hybridized atoms in bombykol is Z. Find the value (Z-5) _____