Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: PYTHIA Status Report   Recent improvements in the PYTHIA event generator are summarized: new hard
subprocesses, gamma*-gamma* physics, QCD final-state showers, and more.

12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
16
The categories of this paper are: stat
14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an