Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A family of well-behaved Karmarkar spacetime describing interior of
  relativistic stars
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
5
The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org
29
The categories of this paper are: funct-an
9
The categories of this paper are: nlin
30
The categories of this paper are: q-alg
14
The categories of this paper are: math-ph
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci