Let $\overline{\mathrm{a}}=2\hat{\mathrm{i}}+\hat{\mathrm{j}}-2\hat{\mathrm{k}} \mathrm{and} \overline{\mathrm{b}}=\hat{\mathrm{i}}+\hat{\mathrm{j}},\mathrm{If} \overline{\mathrm{c}}$ is a vector such that $\overline{\mathrm{a}}\cdot \overline{\mathrm{c}}=\left|\overline{\mathrm{c}}\right|,|\overline{\mathrm{c}}-\overline{\mathrm{a}}|=2\sqrt{2}$ and the angle between $\overline{a}\times \overline{\mathrm{b}} \mathrm{and} \overline{c}$ is $60°$ and $\left|\right(\overline{\mathrm{a}}\times \overline{\mathrm{b}})\times \overline{\mathrm{c}}{|}^2=\frac{\mathrm{m}}{\mathrm{n}}$ ,(m,n are co primes) then m-4n = ____