Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Isotope effect and the role of phonon in the Fe-based superconductors
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
22
The categories of this paper are: chao-dyn
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics
25
The categories of this paper are: patt-sol
18
The categories of this paper are: econ
1
The categories of this paper are: cs
6
The categories of this paper are: astro-ph
13
The categories of this paper are: quant-ph