0 -> T1 0 -> T1 0 -> T1 T1 -> 0 0 -> T2 0 -> T2 0 -> T2 T2 -> 0 0 -> T3 0 -> T3 0 -> T3 T3 -> 0 0 -> C1 C1 -> 0 0 -> C2 C2 -> 0 0 -> C3 C3 -> 0