For complete combustion of methanol $C{H}_{3}OH\left(\mathcal{l}\right)+\frac{3}{2}{O}_2\left(g\right)\to C{O}_2\left(g\right)+2H_{2}O\left(\mathcal{l}\right)$ The amount of heat produced as measured by bomb calorimeter is $726 kJ mo{l}^{-1}$ at $27ºC$. The enthalpy of combustion  at constant pressure for the reaction is $-xkJmo{l}^{-1}$, where $x$ is _______(nearest integer) (Given : $R=8.3J{K}^{-1}mo{l}^{-1}$)