Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Magnetoelectronic properties of normal and skewed phosphorene
  nanoribbons
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
25
The categories of this paper are: patt-sol
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
13
The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
6
The categories of this paper are: astro-ph
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat
19
The categories of this paper are: eess