Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Morphodynamics of barchan-barchan interactions investigated at the grain
  scale
1
The categories of this paper are: cs
19
The categories of this paper are: eess
25
The categories of this paper are: patt-sol
4
The categories of this paper are: cond-mat
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph
8
The categories of this paper are: hep-ex