Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Projective surface automorphisms of positive topological entropy from an
  arithmetic viewpoint
35
The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
19
The categories of this paper are: eess