Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Dust coagulation and fragmentation in molecular clouds. I. How
  collisions between dust aggregates alter the dust size distribution
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
30
The categories of this paper are: q-alg
5
The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio