Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Hamiltonian structure for two-dimensional extended Green-Naghdi
  equations
19
The categories of this paper are: eess
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom
6
The categories of this paper are: astro-ph
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
14
The categories of this paper are: math-ph