Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: From MPI to MPI+OpenACC: Conversion of a legacy FORTRAN PCG solver for
  the spherical Laplace equation
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg
17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
6
The categories of this paper are: astro-ph
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ