Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Graphene and its elemental analogue: A molecular dynamics view of
  fracture phenomenon
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
11
The categories of this paper are: hep-lat
20
The categories of this paper are: acc-phys
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin
24
The categories of this paper are: dg-ga
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg