Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A non-stationary problem coupling PDEs and ODEs modelizing an automotive
  catalytic converter
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
21
The categories of this paper are: adap-org
1
The categories of this paper are: cs
9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
23
The categories of this paper are: solv-int