Let \( P \) be the plane passing through the points \( (5,3,0) \), \( (13,3,-2) \) and \( (1,6,2) \). For \( \alpha \in \mathbb{N} \); if the distances of the points \( A(3,4,\alpha) \) and \( B(2,\alpha,a) \) from the plane \( P \) are \( 2 \) and \( 3 \) respectively, then the positive value of \( a \) is:
