Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Fluctuations and correlations of net baryon number, electric charge and
  strangeness in a background magnetic field
5
The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
18
The categories of this paper are: econ
3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph
14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
24
The categories of this paper are: dg-ga