Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Perturbative Approach to the Gravitational Lensing by a Non-spherically
  Distorted Compact Object
17
The categories of this paper are: q-fin
16
The categories of this paper are: stat
2
The categories of this paper are: math
18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci