0 7 5 1 3 8 9->b(4,6,5,1,3,8,9)1->a(2,6,5,1,3,8,9,10,17,15,11,13,18)2->NULL
1 4 6 5 1 3 8 9->b(4,6,5,1,3,8,9)1->a(2,6,5,1,3,8,9,10,17,15,11,13,18)2->NULL
2 [2 6 5 1 3 8 9 10 17 15 11 13 18]->b(4,6,5,1,3,8,9,14,16,18)3->a(2,6,5,1,3,8,9,10,17,15,11,13,18,12,16)4->NULL
3 [4 6 5 1 3 8 9 14 16 18]->b(4,6,5,1,3,8,9)1->a(2,6,5,1,3,8,9,10,17,15,11,13,18)2->NULL
4 [2 6 5 1 3 8 9 10 17 15 11 13 18 12 16]->b(4,6,5,1,3,8,9,14,16,18)3->a(2,6,5,1,3,8,9,10,17,15,11,13,18,12,16)4->NULL