0 -> S 0 -> V S -> 0 V -> 0 I1 -> 0 I2 -> 0 Iv2 -> 0 R1 -> 0 R2 -> 0 J1 -> 0 J2 -> 0 R -> 0 S -> I1 S -> I2 V -> Iv2 I1 -> R1 I2 -> R2 R2 -> J1 R1 -> J2 J1 -> R J2 -> R Iv2 -> R R1 -> S R2 -> S R -> S V -> S