Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Current effects on scattering of surface gravity waves by bottom
  topography
6
The categories of this paper are: astro-ph
28
The categories of this paper are: alg-geom
2
The categories of this paper are: math
35
The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
31
The categories of this paper are: ao-sci