Let $\vec{V}(\theta) = (\cos\theta + \sec\theta)\hat{a} + (\cos\theta - \sec\theta)\hat{b}$, where $\hat{a}$ and $\hat{b}$ are unit vectors and the angle between $\hat{a}$ and $\hat{b}$ is $60^\circ$, then the minimum value of $|\vec{V}|$ is equal to