Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Convex hull of n planar Brownian paths: an exact formula for the average
  number of edges
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
13
The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat