+a0 (1-p3) p1 p1 p p1 p +a0 (1-p3) (1-p1) p2 +a0 (1-p3) p1 (1-p1) +a0 (1-p3) p1 p1 p (1-p1) +a0 (1-p3) (1-p1) (1-p2)