Liquid Solution

If boiling point of urea solution is $100.18^{\circ} \mathrm{C}$ and $K_b$ for water is $0.512 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$, molality of solution is (Boiling point of water $=100^{\circ} \mathrm{C}$)