0 0 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 
5 6 7 8 9 10 11 12 13 14 
Union:
0 0 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 11 12 13 14 
Intersection:
5 6 7 8 9