Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: How many eigenvalues of a product of truncated orthogonal matrices are
  real?
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
3
The categories of this paper are: physics
1
The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
7
The categories of this paper are: hep-th
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
23
The categories of this paper are: solv-int