Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: On the lifespan of classical solutions to a non-local porous medium
  problem with nonlinear boundary conditions
19
The categories of this paper are: eess
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
4
The categories of this paper are: cond-mat
35
The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga