Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: On the stability of the Brazilian presidential regime: a statistical
  analysis
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
2
The categories of this paper are: math
7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg