The concentration of $\mathrm{F}^{-}$ in a saturated aqueous solution of CaF is $6.55 \times 10^{-3} \mathrm{gL}^{-1}$ . The solubility product of $\mathrm{CaF}_{2}$ in water is- [The atomic weight of Ca and F are 40 and 19 respectively]