Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Measurement and Phenomenology of the Proton Structure Function $F_2$
  from ZEUS at HERA
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
26
The categories of this paper are: bayes-an
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
19
The categories of this paper are: eess
6
The categories of this paper are: astro-ph
35
The categories of this paper are: mtrl-th
27
The categories of this paper are: comp-gas