If \( \vec{a}\cdot\vec{b} = 1 \), \( \vec{b}\cdot\vec{c} = 2 \) and \( \vec{c}\cdot\vec{a} = 3 \), then the value of \( \left[ \vec{a}\times(\vec{b}\times\vec{c}), \; \vec{b}\times(\vec{c}\times\vec{a}), \; \vec{c}\times(\vec{b}\times\vec{a}) \right] \) is:
