Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Linear Precoding for Fading Cognitive Multiple Access Wiretap Channel
  with Finite-Alphabet Inputs
27
The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
4
The categories of this paper are: cond-mat
15
The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
13
The categories of this paper are: quant-ph
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org