Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Solar Space Density of the Red Clump Stars and the Scale-length of the
  Thin Disc
19
The categories of this paper are: eess
34
The categories of this paper are: chem-ph
25
The categories of this paper are: patt-sol
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn