$\large\frac{1}{3- \sqrt 8 } -\frac{1}{\sqrt 8 - \sqrt 7 }-\frac{1}{\sqrt 6 - \sqrt 5}+\frac{1}{\sqrt 5 -2}$=_________

Question

$\begin{array}{1 1} 0 \\ 1 \\ 5 \\ 3 \end{array} $