Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The ALFALFA Almost-Dark Galaxy AGC~229101: A Two Billion Solar Mass HI
  Cloud with a Very Low Surface Brightness Optical Counterpart
34
The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex