Let $\overrightarrow{\mathrm{a}}=2\hat{\mathrm{i}}+7\hat{\mathrm{j}}-\hat{\mathrm{k}},\overrightarrow{\mathrm{b}}=3\hat{\mathrm{i}}+5\hat{\mathrm{k}}$ and $\overrightarrow{\mathrm{c}}=\hat{\mathrm{i}}-\hat{\mathrm{j}}+2\hat{\mathrm{k}}.$. Let $\overrightarrow{\mathrm{d}}$ be a vector which is perpendicular to both $\overrightarrow{\mathrm{a}}$ and $\overrightarrow{\mathrm{b}}$ and $\overrightarrow{\mathrm{c}}\cdot \overrightarrow{\mathrm{d}}=12$. Then $\left(-\hat{\mathrm{i}}+\hat{\mathrm{j}}-\hat{\mathrm{k}}\right)\cdot (\overrightarrow{\mathrm{c}}\times \overrightarrow{\mathrm{d}})$ is equal to