Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Classical W-algebras and generalized Drinfeld-Sokolov bi-Hamiltonian
  systems within the theory of Poisson vertex algebras
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph
5
The categories of this paper are: gr-qc
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
16
The categories of this paper are: stat
12
The categories of this paper are: nucl-th