Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: On the three graph invariants related to matching of finite simple
  graphs
19
The categories of this paper are: eess
1
The categories of this paper are: cs
16
The categories of this paper are: stat
26
The categories of this paper are: bayes-an
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
10
The categories of this paper are: q-bio
23
The categories of this paper are: solv-int
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th