Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Two-dimensional relativistic hydrogenic atoms: A complete set of
  constants of motion
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
4
The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
5
The categories of this paper are: gr-qc
15
The categories of this paper are: nucl-ex