Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The "exterior approach" applied to the inverse obstacle problem for the
  heat equation
6
The categories of this paper are: astro-ph
22
The categories of this paper are: chao-dyn
36
The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg