[next] [prev] [prev-tail] [tail] [up]
{ 7, 8 }
{ 2, 3, 4, 5, 6, 16 }
{ }
{ 9, 10, 11, 12, 13, 17 }
{ 1, 14, 15, 18, 19 }
[next] [prev] [prev-tail] [front] [up]