Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The limit of F_p-Betti numbers of a tower of finite covers with amenable
  fundamental groups
17
The categories of this paper are: q-fin
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
6
The categories of this paper are: astro-ph
24
The categories of this paper are: dg-ga
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
36
The categories of this paper are: cmp-lg
26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg