Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Lie symmetries, reduction and exact solutions of the (1+2)-dimensional
  nonlinear problem
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
6
The categories of this paper are: astro-ph
27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol
4
The categories of this paper are: cond-mat
13
The categories of this paper are: quant-ph
37
The categories of this paper are: supr-con
19
The categories of this paper are: eess
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
24
The categories of this paper are: dg-ga
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph