If \( z \) and \( \omega \) are two complex numbers such that \( |z\omega|=1 \) and \( \arg(z)-\arg(\omega)=\dfrac{3\pi}{2} \), then \( \arg\!\left(\dfrac{1-2\bar z\omega}{1+3\bar z\omega}\right) \) is:
(Here \( \arg(z) \) denotes the principal argument of complex number \( z \))
