Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: On the differences in the periodic behaviour of magnetic helicity flux
  in flaring active regions with and without X-class events
8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics
4
The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
15
The categories of this paper are: nucl-ex
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn