Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Optical spectroscopy of 20 Be/X-ray Binaries in the Small Magellanic
  Cloud
34
The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
1
The categories of this paper are: cs
19
The categories of this paper are: eess
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
4
The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg