Three Dimensional Geometry: JEE Main 2020 Mathematics question

Let a plane P contain two lines $\overrightarrow r = \widehat i + \lambda \left( {\widehat i + \widehat j} \right)$, $\lambda \in R$ and $\overrightarrow r = - \widehat j + \mu \left( {\widehat j - \widehat k} \right)$, $\mu \in R$ If Q($\alpha$, $\beta$, $\gamma$) is the foot of the perpendicular drawn from the point M(1, 0, 1) to P, then 3($\alpha$ + $\beta$ + $\gamma$) equals _______.