Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Propagation of Low-Energy Cosmic Rays in Molecular Clouds: Calculations
  in Two Dimensions
14
The categories of this paper are: math-ph
19
The categories of this paper are: eess
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
18
The categories of this paper are: econ
29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph
4
The categories of this paper are: cond-mat
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics