Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: An Halpha-selected sample of cataclysmic variables -- II. Implications
  for CV evolution
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph