JEE Main 2022 · 25 Jun · Shift 1, Mathematics question 23

Let $\theta$ be the angle between the vectors $\vec a$ and $\vec b$, where $|\vec a|=4$, $|\vec b|=3$ and $\theta\in\left(\dfrac\pi4,\dfrac\pi3\right)$. Then
$$\left|\left(\vec a-\vec b\right)\times\left(\vec a+\vec b\right)\right|^2+4\left(\vec a\cdot\vec b\right)^2$$
is equal to ______.