Ionic radii of cation $\mathrm{A}^{+}$and anion $\mathrm{B}^{\prime \prime}$ are 102 and 181 pm respectively. These ions are allowed to crystallize into an ionic solid. This crystal has cubic close packing for $\mathrm{B}^{\prime \prime} . \mathrm{A}^{+}$is present in all octahedral voids. The edge length of the unit cell of the crystal $A B$ is $\_\_\_\_$ pm. (Nearest Integer)