Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Integrable equations and recursion operators related to the affine Lie
  algebras $A^{(1)}_{r}$
18
The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
17
The categories of this paper are: q-fin
12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
2
The categories of this paper are: math
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg