Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: How well can machine learning predict demographics of social media
  users?
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
6
The categories of this paper are: astro-ph
8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
29
The categories of this paper are: funct-an
16
The categories of this paper are: stat