Let \(\vec {a}=\hat{i}+2 \hat{j}+k,\vec {b}=3(\hat{i}-\hat{j}+k)\). Let \( \vec{c}\) be the vector such that \( \vec{a} \times \vec{c}=\vec{b}\) and \( \vec{a} \cdot \vec{c}=3\). Then \( \overrightarrow{\mathrm{a}} \cdot((\overrightarrow{\mathrm{c}} \times \overrightarrow{\mathrm{b}})-\overrightarrow{\mathrm{b}}-\overrightarrow{\mathrm{c}}) \) is equal to: