human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "combinatorial characterization of formal languages"):
  Abstract: This paper is an extended abstract of the dissertation presented by the author for the doctoral degree in physics and mathematics (in Russia). The main characteristic studied in the dissertation is combinatorial complexity, which is a "counting" function associated with a language and returning the number of words of given length in this language. For several classes of languages, a variety of problems about combinatorial complexity and its connections to other parameters of languages are studied. A brief introduction to the topic and the formulations of results are presented. No proofs are given; instead, the papers containing the proofs are cited.

Includes members:
  Member "almost overlap free words and the word problem for the free burnside semigroup satisfying x 2 x 3":
    also connected through other hyperedges:
      (none)
  Member "on ternary square free circular words":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "circularly squarefree words and unbordered conjugates a new approach")
  Member "quotient complexity of closed languages":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "towards a theory of complexity of regular languages")
  Member "quotient complexity of regular languages":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "complexity of the frobenius monoid problem for a finite language")

Question: Please tell me which class the source paper belongs to. The 40 classes are: cs.NA(Numerical Analysis), cs.MM(Multimedia), cs.LO(Logic in Computer Science), cs.CY(Computers and Society), cs.CR(Cryptography and Security), cs.DC(Distributed, Parallel, and Cluster Computing), cs.HC(Human-Computer Interaction), cs.CE(Computational Engineering, Finance, and Science), cs.NI(Networking and Internet Architecture), cs.CC(Computational Complexity), cs.AI(Artificial Intelligence), cs.MA(Multiagent Systems), cs.GL(General Literature), cs.NE(Neural and Evolutionary Computing), cs.SC(Symbolic Computation), cs.AR(Hardware Architecture), cs.CV(Computer Vision and Pattern Recognition), cs.GR(Graphics), cs.ET(Emerging Technologies), cs.SY(Systems and Control), cs.CG(Computational Geometry), cs.OH(Other Computer Science), cs.PL(Programming Languages), cs.SE(Software Engineering), cs.LG(Machine Learning), cs.SD(Sound), cs.SI(Social and Information Networks), cs.RO(Robotics), cs.IT(Information Theory), cs.PF(Performance), cs.CL(Computation and Language), cs.IR(Information Retrieval), cs.MS(Mathematical Software), cs.FL(Formal Languages and Automata Theory), cs.DS(Data Structures and Algorithms), cs.OS(Operating Systems), cs.GT(Computer Science and Game Theory), cs.DB(Databases), cs.DL(Digital Libraries), cs.DM(Discrete Mathematics). Directly output the class name.

gpt: cs.FL(Formal Languages and Automata Theory)