Periodic Table And Periodicity

If the first ionisation enthalpy of $\mathrm{Li}, \mathrm{Be}$ and C respectively are $520,899,1086 \mathrm{~kJ} \mathrm{~mol}^{-1}$. The first ionisation enthalpy (in $\mathrm{kJ} \mathrm{mol}^{-1}$ ) of B will be