If the set of all \( a \in \mathbb{R} - \{1\} \), for which the roots of the equation \( (1 - a)x^{2} + 2(a - 3)x + 9 = 0 \) are positive is \( (-\infty, -\alpha] \cup [\beta, \gamma) \), then \( 2\alpha + \beta + \gamma \) is equal to ________________.
