Variance sum from a joint density

Let $X$ and $Y$ be two continuous random variables having the following joint probability density function $f(x, y) = \begin{cases} x + y, & 0 < x < 1, \; 0 < y < 1 \ 0, & \text{otherwise} \end{cases}$. Then $72(\operatorname{Var}(X) + \operatorname{Var}(Y))$ equals ________ (answer in integer).