Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: An $O(n^{\epsilon})$ Space and Polynomial Time Algorithm for
  Reachability in Directed Layered Planar Graphs
25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
19
The categories of this paper are: eess
8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio