What comes after 6?
7
What comes after 11?
12
What comes after 19?
20
What comes after 4?
5
What comes before 12?
11
What comes after 15?
16
What comes before 5?
4
What comes before 9?
8
What comes after 17?
18
What comes before 4?
3
What comes before 7?
6
What comes after 8?
9
What comes before 13?
12
What comes after 0?
1
What comes after 9?
10
What comes before 3?
2
What comes after 12?
13
What comes before 15?
14
What comes before 18?
17
What comes before 20?
19