Let $\vec{a}=3 \hat{\imath}+\hat{\jmath}-2 \hat{k}, \vec{b}=4 \hat{\imath}+\hat{\jmath}+7 \hat{k}$ and $\overrightarrow{\mathrm{c}}=\hat{\imath}-3 \hat{\jmath}+4 \hat{k}$ be three vectors. If a vectors $\overrightarrow{\mathrm{p}}$ satisfies $\overrightarrow{\mathrm{p}} \times \overrightarrow{\mathrm{b}}= \overrightarrow{\mathrm{c}} \times \overrightarrow{\mathrm{b}}$ and $\overrightarrow{\mathrm{p}} \cdot \overrightarrow{\mathrm{a}}=0$, then $\overrightarrow{\mathrm{p}} \cdot(\hat{\mathrm{i}}-\hat{\mathrm{j}}-\hat{\mathrm{k}})$ is equal to