Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Two-grid algorithms for singularly perturbed reaction-diffusion problems
  on layer adapted meshes
25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph
0
The categories of this paper are: hep-ph