The following redox reaction occurs in basic medium : ${\mathrm{NO}}_3^{-}+\mathrm{Zn}\left(s\right)⟶{\mathrm{Zn}}^{2+}+{\mathrm{NH}}_4^{+}$ when the above reaction is balanced such that the stoichiometric coefficients are in smallest whole number ratio, then the difference of stoichiometric coefficient of Zn(s) and ${\mathrm{OH}}^{-}$ ion will be: