Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Proceedings 15th International Conference on Automata and Formal
  Languages   The 15th International Conference on Automata and Formal Languages (AFL 2017)
was held in Debrecen, Hungary, from September 4 to 6, 2017. The conference was
organized by the Faculty of Informatics of the University of Debrecen and the
Faculty of Informatics of the E\"otv\"os Lor\'and University of Budapest.
Topics of interest covered all aspects of automata and formal languages,
including theory and applications.

9
The categories of this paper are: nlin
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
20
The categories of this paper are: acc-phys
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph