The molar excess Gibbs free energy $(g^{E})$ of a liquid mixture of $A$ and $B$ is given by $$\frac{g^{E}}{RT} = x_{A}x_{B}\left [ C_{1} + C_{2} \left ( x_{A} - x_{B} \right )\right ]$$ where $x_{A}$ and $x_{B}$ are the mole fraction of $A$ and $B$, respectively, the universal gas constant, $R = 8.314 J\:K^{-1}\:\text{mol}^{-1}$, $T$ is the temperature in $K$, and $C_{1}, C_{2}$ are temperature-dependent parameters. At $300\:K$, $C_{1} = 0.45$ and $C_{2} = -0.018$. If $\gamma_{A}$ and $\gamma_{B}$ are the activity coefficients of $A$ and $B$, respectively, the value of $$\int_{0}^{1}\text{ln}\left ( \frac{\gamma _{A}}{\gamma _{B}} \right )dx_{A}$$ at $300\:K$ and $1$ bar is ___________________ (rounded off to the nearest integer).