In the reaction:

$\text{Zn}\text{+}{\text{NaNO}}_{\text{3}}\text{+}\text{NaOH }\to {\text{Na}}_{\text{2}}{\text{ZnO}}_{\text{2}}\text{+}\text{A}\text{+}{\text{H}}_{\text{2}}\text{O}$

The sum of stoichiometric coefficients of $\mathrm{Z}\mathrm{n}$ and $\text{A}$ in the balanced reaction with simplest integer coefficient is