Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Transmission and reflection of strongly nonlinear solitary waves at
  granular interfaces
7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas