The reaction of cyanamide, $\mathrm{NH}_2 \mathrm{CN}_{(\mathrm{s})}$ with oxygen was run in a bomb calorimeter and $\Delta \mathrm{U}$ was found to be $742.24 \mathrm{~kJ} \mathrm{~mol}^{-1}$. The magnitude of $\Delta \mathrm{H}_{298}$ for the reaction
$\left(\mathrm{NH}_2 \mathrm{CN}_{(\mathrm{s})}+\frac{3}{2} \mathrm{O}_2(\mathrm{~g}) \rightarrow \mathrm{N}_{2(\mathrm{~g})}+\mathrm{O}_2(\mathrm{~g})+\mathrm{H}_2 \mathrm{O}_{(l)}\right.$
is $\_\_\_\_$ kJ . (Rounded off to the nearest integer) [Assum ideal gases and $\mathrm{R}=8.314 \mathrm{~J} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}$ ]