Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Formation of Planets   This paper reviews the dynamics of the growth of solid particles from
micron-sized dust grains to planets in protostellar accretion disks. The
formation and orbital evolution of giant protoplanets is also discussed.

2
The categories of this paper are: math
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
1
The categories of this paper are: cs