2 molal solution of a weak acid HA has a freezing point of $3.885^{\circ} \mathrm{C}$. The degree of dissociation of this acid is $\_\_\_\_$ $\times 10^{-3}$. (Round off to the Nearest Integer). [Given: Molal depression constant of water $=1.85$ $\mathrm{K} \mathrm{kg} \mathrm{mol}^{-1}$ Freezing point of pure water $\left.=0^{\circ} \mathrm{C}\right]$