If $x= \large\frac{\sqrt 2 +1}{\sqrt 2 -1}$$y= \large\frac{\sqrt 2 -1}{\sqrt 2 +1}$ then $x^2+xy+y^2 $ is _______

Question

$\begin{array}{1 1} 36 \\ 6 \\ 35 \\ 3 \end{array} $