Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Superconductivity of monolayer Mo$_2$C: the key role of functional
  groups
5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
12
The categories of this paper are: nucl-th
26
The categories of this paper are: bayes-an
20
The categories of this paper are: acc-phys
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th