Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Inner-most stable circular orbits in extremal and non-extremal
  Kerr-Taub-NUT spacetimes
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
16
The categories of this paper are: stat
2
The categories of this paper are: math
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
8
The categories of this paper are: hep-ex
36
The categories of this paper are: cmp-lg
4
The categories of this paper are: cond-mat
15
The categories of this paper are: nucl-ex
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
13
The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess
6
The categories of this paper are: astro-ph