Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The stability of strong waves and its implications for pulsar wind
  shocks
24
The categories of this paper are: dg-ga
4
The categories of this paper are: cond-mat
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess
34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc